Produced by Chuck Greif, deaurider and the Online
Distributed Proofreading Team at http://www.pgdp.net (This
file was produced from images generously made available
by The Internet Archive)







                [Illustration: PROSPECTING THE GROUND.]

                            [Illustration]




                        UNDERGROUND TREASURES:

                      HOW AND WHERE TO FIND THEM.

                                 A KEY

             FOR THE READY DETERMINATION OF ALL THE USEFUL
                  MINERALS WITHIN THE UNITED STATES.

                         BY JAMES ORTON, A.M.,

   _Late Professor of Natural History in Vassar College, N. Y.; Cor.
        Mem. of the Academy of Natural Sciences, Philadelphia,
            and of the Lyceum of Natural History, New York;
              Author of “The Andes and the Amazon,” etc._

                     A NEW EDITION WITH ADDITIONS.

                             ILLUSTRATED.

                             PHILADELPHIA:
                       HENRY CAREY BAIRD & CO.,

           INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS,

                          810 WALNUT STREET.

                                 1881.

      Entered according to Act of Congress, in the year 1872, by
                      WORTHINGTON, DUSTIN & CO.,

   In the Office of the Librarian of Congress, at Washington, D. C.

                              Copyright:

                        HENRY CAREY BAIRD & CO.
                                 1881.




_Table of Contents._


 CHAPTER I.

 .....PAGE.

 INTRODUCTION.--Money in the Rocks--The Underground Wealth
 of our Country--Valuable Minerals Disguised--How Great Fortunes are
 Missed--Number of Minerals in the United States--Object of this Work
 and How to Use it--The Best Mineral Regions.....9


 CHAPTER II.

 DIRECTIONS FOR DETERMINING SPECIMENS BY THE KEY.--How to
 Test Minerals with the Simplest Means--Prospecting with a Jack-knife
 and Common Sense--Use of the Key--How to Tell Pyrites from Gold, and
 Quartz from Diamond--All the Useful Minerals Grouped According to
 Hardness and Color.....15


 CHAPTER III.

 DESCRIPTIVE LIST OF USEFUL MINERALS.--The Gems--Precious
 Metals--Valuable Ores and Useful Minerals of the United States from
 Agate to Zinc--Their Distinguishing Characters, Uses and Localities--A
 Mineralogy for Miners--Agate--Alum--Amethyst--Anthracite--Antimony
 Ore--Asbestus--Asphaltum--Azurite--Baryta--Bituminous
 Coal--Blende--Bog Iron Ore--Brittle Silver Ore--Brown
 Coal--Calamine--Cannel Coal--Carnelian--Celestine--Cerussite--Chromic
 Iron--Cinnabar--Cobalt Pyrites--Copper--Copper
 Glance--Copper Nickel--Copper Pyrites--Diamond--Emery--Fluor
 Spar--Franklinite--Galena--Garnet--Gold--Graphite--Gray Copper
 Ore--Gypsum--Horn Silver--Iron Pyrites--Jasper--Kaolin--Lenticular
 Iron Ore--Limonite--Magnetic Iron Ore--Magnetic
 Pyrites--Malachite--Manganese Spar--Marble--Mica--Micaceous Iron
 Ore--Nitre--Oxyd of Manganese--Platinum--Red Copper Ore--Red
 Hematite--Red Silver Ore--Rensselaerite--Rock Crystal--Rock
 Salt--Rutile--Serpentine--Silicate of Copper--Silver--Silver
 Glance--Smaltine--Smithsonite--Spathic Iron--Specular
 Iron--Spinel Ruby--Steatite--Strontianite--Sulphur--Tin
 Ore--Topaz--Tourmaline--Variegated Copper
 Ore--Wad--Willemite--Zincite.....20


 CHAPTER IV.

 PROSPECTING FOR DIAMONDS, GOLD, SILVER, COPPER, LEAD AND
 IRON.--Mineral Riches, how Discovered--Indications--Searching
 for Diamonds, and how to Distinguish them--Paying Localities of
 Gold--“Fool’s Gold”--Prospecting for Silver and Copper--Where to Look
 for Lead and Iron.....81


 CHAPTER V.

 ASSAY OF ORES.--When an Ore will Pay--Washing for Gold and
 Platinum--How to Assay Gold in the Simplest Way--To Test any Rock
 for Gold and Silver--To Find the Purity of Gold--To Detect and Assay
 Silver Ores--Assay of Copper, Iron, Zinc, Tin and Lead Ores-Ready
 Method of Testing Graphite.....92


 CHAPTER VI.

 MINERAL SPRINGS.--What are Mineral Springs--General
 Location--Gas Springs--Iron Springs--Sulphur Springs--Alum
 Springs--Epsom Springs--Salt Springs--Warm Springs--Artesian Wells and
 Oil Wells, and Where to Bore for Them.....105


 CHAPTER VII.

 ARTIFICIAL JEWELRY--HOW MADE AND HOW DETECTED.--Mock
 Diamonds--“Paris Brilliants”--The Manufacture of Pastes--False Ruby,
 Topaz, Sapphire, Emerald and Carnelian--How to Distinguish True and
 False Gems--Imitation Pearl and Coral--Artificial Gold--List of
 Precious Stones.....114


 CHAPTER VIII.

 DISCOVERY OF GOLD IN CALIFORNIA.....127


 CHAPTER IX.

 DISCOVERY OF SILVER IN NEVADA, AND UNITED STATES GOLD AND SILVER
 STATISTICS.....134



                               INSCRIBED

                                  TO

                     ROSSITER W. RAYMOND, PH. D.,

                             UNITED STATES

                  COMMISSIONER OF MINING STATISTICS;

                             EDITOR OF THE

                    ENGINEERING AND MINING JOURNAL;

                               AUTHOR OF

                     “The Mines of the West,” etc.




                             _Underground
                              Treasures._




NOTE.


This little work was not written for mineralogists, but expressly for
the landholder, the farmer, the mechanic, the miner, the laborer, even
the most unscientific. It is designed to enable such to discover for
themselves, minerals and ores of use in the arts, and thus develop the
resources and ascertain the value of any particular farm or region. It
may save the owner from ruinous bargains, and may reveal a mine of
mineral wealth, more sure and more profitable than any bank.




_List of Illustrations._


PROSPECTING THE GROUND                                      Frontispiece.

FAC-SIMILE OF NUGGET OF GOLD, (California,)       Illuminated Title Page.

PROSPECTING DIAMOND DRILL                                             40

WASHING AURIFEROUS SANDS                                              47

SEARCHING FOR DIAMONDS                                               121

THE SAW-MILL OF COLOMA                                               129

   (The place where Gold was first discovered in California.)




A KEY FOR THE READY DETERMINATION OF ALL THE USEFUL MINERALS WITHIN THE
UNITED STATES.




CHAPTER I.

INTRODUCTION.

     MONEY IN THE ROCKS--THE UNDERGROUND WEALTH OF OUR COUNTRY--VALUABLE
     MINERALS DISGUISED--HOW GREAT FORTUNES ARE MISSED--NUMBER OF
     MINERALS IN THE UNITED STATES--OBJECT OF THIS WORK AND HOW TO USE
     IT--THE BEST MINERAL REGIONS.


Minerals head the list of the sources of our nation’s wealth. Gold,
iron, coal and marble have not only contributed largely to the
enterprise and opulence of America, but at this very moment they exert a
commanding influence in political circles. No one can prophesy the
greatness of the commercial power which is sure to rise on their
foundations.

No other country can boast of such vast and valuable mineral deposits.
Yet our country is not half developed. Treasures lie undiscovered in our
mountains and under our farms,--gems of “purest ray serene” and still
more precious metals. Some will be accidentally brought to light; but
the majority are so disguised that their real nature is not seen. How
unpromising are the best ores of iron, zinc and silver and the rarest
gems! Then, again, there is “mimicry” in the mineral kingdom; worthless
stones are often good imitations of the valuable, and fortunes have been
sunk in mining pyrites for gold, mica for silver and slate for coal. But
if we wait for mineralogists to develop our mineral resources, we must
wait a millenium, our country is so vast and scientific laborers so few.
Fortunately, however, nature has stamped upon each mineral some peculiar
feature or assemblage of characters which enable any one with average
common sense to distinguish those which are of value in the arts.

The object of this work is to point out those distinctions so clearly
and in popular language that those who do not claim to be scientific may
determine specimens for themselves; in other words, to furnish _a key
for the ready determination of all the useful minerals within the United
States_.[1]

Two hundred and forty-four mineral species have been found within the
bounds of the Union. Of these only one-third are of any use to the
practical man. These eighty have certain general characters in common,
but always some specific differences. The object is to divide them into
groups, as the botanist divides the plants, and then to separate the
individuals by some properties or features peculiar to each. Only those
minerals are mentioned which are useful: any specimen, therefore, which
does not fit any of the descriptions given, may be considered of no
special value. By the term “color,” is meant the color of a fresh
fracture, for the exposed surface often misrepresents the true aspect.
Exact color is not meant, but “red” stands for reddish, “yellow” for
yellowish, “white” for a light gray up to the perfectly transparent.
“Magnetic” means that the specimen disturbs the needle of a compass, or
that a magnet will take up fine particles. A mineral is “opaque” if the
light will not pass through either the edges or a thin fragment. A
“translucent” mineral is either clear as crystal or only allows light to
pass dimly through a thin portion. “Effervescence” is the bubbling
produced by the escape of a gas, as in soda-water. “Gravity” is the
weight compared with that of an equal bulk of water. In the majority of
cases the specimen can be determined without it; but there may be
several doubtful cases which can be settled only by obtaining the
gravity. This is done by first weighing a fragment of the mineral in a
small apothecary or jeweler’s balance, reckoning it in grains. Then by
a thread suspend it below one of the scales in a tumbler of water,
taking care that the specimen is covered with water and does not touch
the sides. Subtract the weight in grains as it hangs in the water from
the first weight, and divide the first weight by the difference: the
result is the gravity. Five per cent. should be allowed for impurities.
Where exactness is not required, the gravity of a specimen may be judged
by comparing it with well-known substances. Thus,

The gravity of anthracite coal is about   1.5
The gravity of brick is about             1.8
The gravity of clay is about              2.0
The gravity of marble and glass is about  2.5
The gravity of slate is about             2.8
The gravity of cast-iron is about         7.0
The gravity of copper is about            9.0
The gravity of lead is about             11.0

If the gravity of a mineral is 1.5, a cubic inch of it will weigh about
¾ ounce; if 2., 1 oz.; if 2.5, 1¼ oz.; if 3., 1½ oz.; if 4., 2 oz.; if
5, 2½ oz., etc.

There is no section of our country that may not reward a diligent search
for precious or useful minerals. The rocks, however, between the
Alleghanies and the Atlantic and between the Rocky Mountains and the
Pacific furnish the greater variety and abundance. Here are found the
best ores. Gold and silver seem to abound more on the western than
eastern sides of both mountain-chains. A trap-region, like the shore of
Lake Superior and the Connecticut River Valley, is likely to be a good
locality for copper and iron. The Mississippi Valley, or the region of
Bituminous Coal, furnishes chiefly iron and lead; gold, silver and
copper are seldom found. In general, where the layers of rock lie level
and contain fossil shells, it is a locality good only for soft coal,
(New York excepted), iron ore, gypsum and salt. The regions of granite,
slate, limestone, marble, etc., offer the greatest inducement to search
for useful minerals.




CHAPTER II.

DIRECTIONS FOR DETERMINING SPECIMENS BY THE KEY.

     HOW TO TEST MINERALS WITH THE SIMPLEST MEANS--PROSPECTING WITH A
     JACK-KNIFE AND COMMON SENSE--USE OF THE KEY--HOW TO TELL PYRITES
     FROM GOLD AND QUARTZ FROM DIAMOND--ALL THE USEFUL MINERALS GROUPED
     ACCORDING TO HARDNESS AND COLOR.


First see whether it will scratch common window-glass. If it will make
the least mark, it belongs to division A; if not, it is to be found in
group B. Next notice whether the light will shine through it: if it does
not pass through even the edges or a thin splinter, it is opaque; if any
light is allowed to pass, it is translucent. With a knife see if it is
harder or softer than pure white marble; then, noting its color, compare
it with the descriptions of minerals referred to by the numbers. If it
agree with none, it may be considered of no use in the arts. To make
doubly sure, get the gravity as described on page 12.

_Examples_: Suppose we have an unknown mineral in hand. We first try to
scratch glass with it and find it impossible. It therefore belongs to
section B. Next we find it is opaque and yellow, and evidently heavier
and harder than marble. It must be one of two: 44 attracts the
compass-needle, and this will not; it is consequently 26 or _Copper
Pyrites_, if it agree with the description. If not, it is something of
no great value.

You have found what you think is a diamond, Does the specimen scratch
glass? Yes, easily, and is brittle. Can you see through it? You say it
is clear as glass. Look now under section A, “translucent” series,
number 6 (for it is colorless), and decide which of the four it is. The
first one (27), is diamond; but do not let your wishes _make_ it agree.
Turning to the description, you read that it can not be scratched with
a file or worn down on a grindstone. This decides against it. Besides,
the gravity (2.5) is too little. With the next (57) it agrees perfectly,
and you need not go further. Should the specimen, however, agree very
well with rock crystal, only that its gravity (3.5) is too great, then
it is topaz.

☞ All minerals that scratch glass are brittle, and all (save 32 and
46) are infusible or melt with great difficulty.

☞ The following minerals will burn, evaporate or melt without a flux
in an ordinary fire: Nos. 2, 4, 5, 7, 10, 13, 14, 16, 18, 19, 21, 23,
24, 26, 29, 33, 35, 37, 44, 53, 55, 62, 63, 70, 71, 75. All but the
following are heavier than marble: 2, 4, 6, 7, 10, 14, 16, 34, 36, 40,
47, 48, 56, 60, 61, 69, 71. Nos. 2, 50 and 58 alone dissolve in water.

☞ In determining color, be sure you have a fresh surface, for the
outside is often deceptive. By “blow-pipe” is meant the tapering tube
used by watch-makers.


A.

WILL SCRATCH GLASS.

I. OPAQUE.

(1) Black: 12, 20, 28, 30, 42, 43, 51, 54, 67, 72.
(2) Brown: 12, 28, 42, 59, 72, 77.
(3) Red: 39, 46, 54. 59. 67.
(4) Yellow: 38, 72, 77.
(5) Gray: 22, 28, 72.
(6) White: 64.

II. TRANSLUCENT.

(1) Brown: 32, 59, 72, 77.
(2) Red: 17, 32, 46, 59, 68, 73, 74.
(3) Yellow: 32, 59, 72, 73, 77.
(4) Green: 74, 77.
(5) Violet-blue: 3.
(6) White: 27, 57, 73, 77.
(7) Banded or clouded: 1.


B.

WILL NOT SCRATCH GLASS.

I. OPAQUE.

Harder than white marble.[2]    | Softer than white marble.
                                |
(1) Black: 11, 35, 47.          | 4, 7, 10, 12, 13, 14, 16, 24,
                                | 34, 37, 49, 51, 55, 56, 76.
(2) Brown: 66, 75.              | 12, 14, 21.
(3) Red: 44, 53, 75.            | 21, 23, 41, 55.
(4) Yellow: 26, 44.             | 12, 33, 56.
(5) Green: 45.                  | 60, 61.
(6) Gray: 35, 66.               | 5, 24, 31, 34, 36, 49, 56, 63,
                                | 69.
(7) White: 6, 9, 11.            | 36, 40, 56, 62.

II. TRANSLUCENT.

(1) Black: 11.                  | 55.
(2) Brown: 9, 11, 65, 66.       | 48.
(3) Red: 9, 11, 18, 53, 78.     | 36, 55.
(4) Yellow: 9, 11, 15, 29,      | 48, 71.
47, 78.                         |
(5) Green: 29, 45, 65, 70.      | 48, 60, 61.
(6) Blue: 8, 18, 29, 47.        |
(7) Gray: 19, 47, 65, 66.       | 37, 69.
(8) White: 18, 47.              | 2.
(9) Mottled or Banded: 47.      |
--------------------------------+----------------------------------




CHAPTER III.

DESCRIPTIVE LIST OF USEFUL MINERALS.

     THE GEMS--PRECIOUS METALS--VALUABLE ORES AND USEFUL MINERALS OF THE
     UNITED STATES FROM AGATE TO ZINC--THEIR DISTINGUISHING CHARACTERS,
     USES AND LOCALITIES--A MINERALOGY FOR MINERS.


1.--AGATE.

This stone is a mixture of several kinds of quartz, mainly the white,
red, brown and black, disposed in layers or clouds. The layers are
zigzag, circular or in straight bands (onyx). Occurs in irregular
rounded masses; not very translucent; not altered by heat or acids;
cannot be cut with a knife nor split into plates; takes a high polish;
lustre glassy; gravity 2.5.

VALUE.--Used for jewelry and ornamental work, mortars, vases,
knife-handles, burnishers, etc. The colors are deepened by boiling in
oil and then in sulphuric acid.

LOCALITIES.--Found in granite and trap regions, generally by the shores
of rivers, lakes and the sea; as, north-west shore of Lake Superior;
Missouri, Columbia, Colorado and Connecticut Rivers; Crescent City,
Cal.; Hancock County, Ga.; near Tampa Bay, Fla.; Fulton, Penn.;
Yellowstone Lake, Wy.[3]


2.-ALUM.

Occurs in mealy or solid crusts, often fibrous; dissolves in water;
tastes sweetish-astringent; melts and froths up when heated.

VALUE.--Extensively used in dyeing and calico-printing, candle-making,
dressing skins, clarifying liquors and in pharmacy.

LOCALITIES.--Found incrusting and impregnating dark slaty rocks, with
yellow streaks. Cape Sable, Md.; Cleveland County, N. C.; coal slates
on Ohio River, and in caves in Sevier, De Kalb, Coffee and Franklin
Counties, Tenn.; also Esmeralda and Storey Counties, Nev.


3.--AMETHYST.

Same as _Rock Crystal_, but colored purple or bluish violet. Generally
in clustered crystals.

VALUE.--When clear and finely colored, it is a favorite gem.

LOCALITIES.--Usually found with agate. Keweenaw Point, Pic Bay and
Gargontwa on Lake Superior; Bristol, R. I.; Surry, N. H.; East Bradford,
Aston, Chester, Thornbury, Edgemont, Sadsbury, Birmingham, Middletown
and Providence, Penn.; Greensboro, N. C.


4.--ANTHRACITE.

Occurs massive; compact; high lustre; brittle; breaks with a curved
surface; will not scratch marble; burns, but not readily, with a pale
blue flame and little smoke; will not form coke by roasting; gravity
1.4 to 1.8.

VALUE.--Used for fuel and sometimes cut into inkstands, etc.

LOCALITIES.--Found in beds between slates and sandstones, and east of
the Alleghany range only, as Eastern Pennsylvania; Portsmouth, R. I.;
Mansfield, Mass.; North Carolina. No workable beds will be found in New
York.

The rocks in anthracite regions are tilted, bent and broken, never level
to any great extent. Impressions of leaves are good indications.


5.--ANTIMONY ORE.

Occurs fibrous or granular; color lead gray, often tarnished; shining
lustre, brittle; but thin pieces can be cut off with a knife; melts in a
candle, at a high heat passing off in vapor; gravity 4.5.

VALUE.--The source of the antimony of commerce, containing seventy per
cent.

LOCALITIES.--Found associated with _Silver_, _Spathic Iron_, _Blende_,
_Baryta_ and _Quartz_. Carmel, Me.; Lyme, N. H.; Soldier’s Delight,
Md.; Aurora, Nev.; San Amedio Cañon and Tulare County, Cal.


6.--ASBESTUS.

Occurs finely fibrous, flax-like; flexible, not elastic; silky lustre,
sometimes greenish; gravity 3.

VALUE.--Used for lining safes and steam-packing, and for making
incombustible cloth, lamp-wicks, etc.

LOCALITIES.--Found in granite-regions east of the Alleghanies; often
with _Serpentine_. Brighton, Dedham, Newbury, Pelham and Sheffield,
Mass.; Milford, West Farms, Winchester and Wilton, Conn.; Chester, Mt.
Holly and Cavendish, Vt.; Patterson, Phillipstown, Monroe and Staten
Island, N. Y.; Brunswick, N. J.; East Nottingham, Goshen and Aston,
Penn.; Bare Hills and Cooptown, Md.; Barnet’s Mills, Va.


7.--ASPHALTUM.

Occurs massive; brittle; breaking with high lustre like hardened tar,
and with curved surface; melts and burns readily with flame and smoke;
gravity 1.2, sometimes floats on water.

VALUE.--Used for cements and varnishes.

LOCALITIES.--Found generally near the surface. Near the coast of Santa
Barbara, Cal.; West Virginia, twenty miles south of Parkersburg.


8.--AZURITE.

Occurs in crystals and masses with glassy lustre, or earthy and dull;
brittle; crackles and blackens, and finally fuses by heat; dissolves
with effervescence in nitric acid; gravity 3.5.

VALUE.--A valuable ore of copper, containing sixty per cent.

LOCALITIES.--Found chiefly in lead and copper mines. Perkiomen lead
mine, Cornwall, Phoenixville and Nicholson’s Gap, Pa; near New
Brunswick, N. J.; near Mineral Point, Wis.; Polk County, Tenn.;
Calaveras and Mariposa Counties, Cal.; near Virginia City, Mont.


9.--BARYTA, OR HEAVY SPAR.

Occurs in crystals, plates and masses; powder white; brittle; crackles
when strongly heated; not dissolved in acids; easily distinguished by
its weight; gravity 4.5, or twice as heavy as _Gypsum_.

VALUE.--Used extensively as white paint and in pottery.

LOCALITIES.--Found in mining districts, often with lead, copper and iron
ores, and in limestone. Piermont, N. H.; Hatfield, Southampton and
Leverett, Mass.; Cheshire and Berlin, Conn.; Pillar Point, Rossie,
Carlisle, Scoharie, De Kalb, Gouverneur, N. Y.; Fauquier and Buckingham
Counties, Va.; Union, Gaston and Orange Counties, N. C.; near Paris, and
in Anderson, Fayette, Mercer and Owen Counties, Ky.; on Brown’s Creek
and Haysboro, Tenn.; Bainbridge, O.; Scales Mound, Ill.; Prince Vein,
Lake Superior; Mine-a-Barton, Mo.; near Fort Wallace, N. M.; Ingo
County, Cal.


10.--BITUMINOUS COAL.

Occurs in masses, beds or seams; softer and duller than _Anthracite_;
often a bright pitchy lustre; brittle, showing a slaty or jointed
structure rather than curved surface; powder black; burns readily with
yellow flame; by roasting forms coke; gravity 1.5 or less.

VALUE.--Used for fuel and the production of gas, coke, carbolic acid and
aniline.

LOCALITIES.--Found west of Harrisburg, Pa., in rocks (slates and
sandstones) less disturbed than in the _Anthracite_ region. Western
Pennsylvania; South-east Ohio; West Virginia; Eastern Kentucky and
Tennessee to Tuscaloosa; North-west Kentucky; Illinois; Iowa; Missouri;
Kansas; Arkansas; Northern Texas; Central Michigan; Owyhee County,
Idaho; Deer Lodge and Gallatin Counties and sixty miles north-east of
Bannock, Mont.


11.--BLENDE.

Occurs in crystals and masses; waxy lustre, but not always very
apparent; usual color, rosin-yellow to dark brown; brittle; the powder,
which is whitish to reddish-brown, dissolves in muriatic acid giving off
the odor of rotten eggs; by roasting gives off sulphur-fumes; infusible
alone, but on charcoal at a high heat gives off white fumes; gravity 4.

VALUE.--An ore of zinc (containing sixty-six per cent.) and a source of
white vitriol. Often worked for its _Silver_ and _Gold_.

LOCALITIES.--Found with lead and other ores. Lubec and Bingham, Me.;
Eaton, Warren and Shelburne, N. H.; Sterling, Southampton and Hatfield,
Mass.; Brookfield, Berlin, Roxbury and Monroe, Conn.; near Wurtzboro’,
Cooper’s Falls, Mineral Point, Fowler, Ancram, Clinton and Spraker’s
Basin, N. Y.; Wheatley and Perkiomen lead-mines, Schuylkill,
Shannonville and Friedensville, Pa.; Austin’s lead-mine, Va.; Haysboro’,
Brown’s Creek and Polk Counties, Tenn.; Prince Vein, Mich.; Dubuque,
Ia.; Warsaw, Rosiclare and Galena, Ill.; Shullsburg, Wis.; Stillwater,
Minn.


12.--BOG IRON ORE.

Occurs in masses or beds, looking much like hard brown earth; loose or
porous and earthy, rather than compact and nodular; powder
yellowish-brown; when strongly heated becomes black and magnetic;
gravity nearly 4. An earthy yellow variety is called _Yellow Ochre_.

VALUE.--An important ore, yielding thirty-five per cent.

LOCALITIES.--Found in low, marshy grounds; widely distributed. Lebanon,
N. H.; Berkshire and Plymouth Counties, Mass.; Columbia, St. Lawrence,
Franklin and Jefferson Counties, N. Y.; New Limerick, Katahdin,
Newfield, Shapleigh, Argyle, Clinton, Williamsburg and Lebanon, Me.;
Darien and Martin Counties, Ind.; Monmouth County, N. J.; Somerset and
Worcester Counties, Md.; Michigan, Ohio, Illinois, Wisconsin, etc.


13.--BRITTLE SILVER ORE.

Occurs in crystals and masses; metallic lustre; tarnishes yellow, gray
and finally black; easily cut or broken; when heated gives off fumes of
sulphur and antimony, affording a button of silver; dissolved in nitric
acid, it silvers copper placed in it; gravity 6.

VALUE.--A rich ore of silver, containing over sixty per cent.

LOCALITIES.--Found in veins with other silver ores, in Nevada and Idaho.


14.--BROWN COAL.

Occurs like _Bituminous Coal_, but usually brownish-black with less
lustre, and often showing a woody or slaty structure; powder always
brown; contains fossil plants; gravity between 1.2 and 1.5.

VALUE.--Inferior to No. 10. Makes no coke. Can be used in the
manufacture of alum.

LOCALITIES.--Found in thin veins or elliptical masses, never in
extensive layers like Pennsylvania coal. Near Richmond, Va.; Deep
River, N. C.; Michigan, Missouri, Texas; Evanston, Utah; Coal Creek and
Bellmonte, Col.; Boreman, Dearborn River and Greenhorn Gulch, Mont.


15.--CALAMINE.

Occurs in crystals and masses; glossy lustre; harder than marble;
brittle; heated it swells up, becomes opaque and emits a green light;
dissolves, when powdered, in hot sulphuric acid without effervescence;
gravity 3.4.

VALUE.--An ore of zinc yielding from forty to sixty per cent.

LOCALITIES.--Found in limestone rock with other ores. Friedensville,
Perkiomen, Phœnixville, Lancaster and Selin’s Grove, Pa.; Austin’s
Mines in Wythe County, Va.; Claiborne County, Tenn.; Jefferson County,
Mo.


16.--CANNEL COAL.

Occurs in compact masses; dull lustre; brittle, breaking with a curved
surface; burns readily but does not melt; does not soil the fingers;
gravity about 1.2.

VALUE.--Used for fuel and for making gas, oil and ornaments.

LOCALITIES.--Found in the Mississippi Valley; Kentucky; Lick, Ohio;
Illinois; Moniteau County, Mo.; Kenawha County, Va.; Beaver County, Pa.


17.--CARNELIAN.

Occurs in masses or pebbles; at first grayish, but by exposure to the
sun becomes uniform flesh, red or brown, never striped,--although
_Carnelian_ may form one of the bands of an _Agate_; brittle, breaking
with a curved surface; very hard; takes a fine polish; glassy or
resinous lustre; gravity 2.6.

VALUE.--Used for jewelry. When of two layers, white and red, (properly
called sardonyx,) it is used for cameos.

LOCALITIES.--Same as _Agate_.


18.--CELESTINE.

Occurs crystallized, fibrous and massive; color white, often faint
bluish; glassy lustre; very brittle; under the blow-pipe crackles and
melts, tinging the flame red; does not dissolve in acids; gravity 4.

VALUE.--The source of nitrate of strontia, used in fire-works.

LOCALITIES.--Found in limestone, gypsum and sandstone. Rossie,
Schoharie, Chaumont Bay, Depauville and Stark, N. Y.; Frankstown, Pa.;
Strontian and Put-in-Bay Islands, Lake Erie; near Nashville, Tenn.; Fort
Dodge, Iowa.


19.--CERUSSITE.

Occurs in crystals, in powder or masses; glassy lustre; brittle;
dissolves in nitric acid with effervescence; heated strongly on charcoal
crackles and fuses, giving a globule of lead; gravity 6.4.

VALUE.--A rich ore of lead yielding seventy-five per cent.

LOCALITIES.--Found in lead mines. Southampton, Mass.; Perkiomen,
Phœnixville, Charlestown and Schuylkill, Pa.; Wythe County, Va.;
Washington Mine, N. C.; Valle’s Diggings, Mine-la-Motte and
Mine-a-Burton, Mo.; Davies and Rock Counties, Ill.; Blue Mounds, Wis.;
Ingo County, Cal.


20.--CHROMIC IRON.

Occurs in compact masses; powder dark brown; small pieces sometimes
attracted by the magnet; brittle, breaking with uneven surface; with
borax melts into a green globule; not acted upon by acids; little
lustre; gravity 4.4.

VALUE.--Used in making the chrome pigments.

LOCALITIES.--Found in _Serpentine_. Bare Hills, Cooptown and north part
of Cecil County, Md.; Nottingham, W. Goshen, Williston, Fulton, Mineral
Hill, Texas and Unionville, Pa.; Jay, New Fane, Westfield and Troy, Vt.;
Chester and Blanford, Mass.; Loudon County, Va.; Yancy County, N. C.;
North Almaden, New Idria and Coloma, Cal.


21.--CINNABAR.

Occurs in granular or earthy masses; resembles iron-rust, but is a
yellowish-red; powder scarlet; easily cut with a knife; thrown on
red-hot iron, evaporates, giving off odor of sulphur; rubbed on copper,
“silvers” it; gravity 9, or about as heavy as _Copper_.

VALUE.--The source of mercury (containing eighty-four per cent.) and
vermilion.

LOCALITIES.--Found in slate and limestone rocks. Centreville,
Coulterville, New Idria and New Almaden, and Lake and San Luis Obispo
Counties, California; Idaho.


22.--COBALT PYRITES.

Occurs crystallized and massive; does not scratch glass easily; metallic
lustre; tarnish, copper-red; powder, blackish-gray; brittle; heated on
charcoal gives off sulphur fumes; heated with borax gives a blue glass;
gravity 5.

VALUE.--An ore of cobalt, yielding twenty per cent.

LOCALITIES.--Usually found in slate or granite rocks with _Copper
Pyrites_. Mineral Hill, Md.; Mine-la-Motte, Mo.


23.--COPPER.

Occurs in irregular masses; metallic lustre; can be cut with a knife;
malleable; ductile; fusible; gravity 8.8.

VALUE.--A source of copper and silver.

LOCALITIES.--Most abundant in the trap and “freestone” regions. New
Brunswick, Somerville, Schuyler’s and Flemington, N. J.; Whately, Mass.;
Cornwall and Shannonville, Pa.; Polk County, Tenn.; Keweenaw Point, Lake
Superior; Calaveras, Amador and Santa Barbara Counties, Cal.; on Gila
River, Ariz.


24.--COPPER GLANCE.

Occurs crystallized and massive; color, blackish lead-gray, often
tarnished blue or green; nearly as hard as marble; brittle; a splinter
will melt in a candle, giving off the odor of sulphur; dissolved in
nitric acid, it will coat a knife-blade with copper; metallic lustre;
gravity 5.5.

VALUE.--An ore of copper, yielding seventy-five per cent.

LOCALITIES.--Found at copper-mines. Simsbury, Bristol and Cheshire,
Conn.; Schuyler’s Mines, N. J.; Orange County, Va.; near Newmarket, Md.;
Lake Superior copper-region; La Paz, Arizona; Washoe, Humboldt, Nye and
Churchill Counties, Nev.


25.--COPPER NICKEL.

Occurs in masses; metallic lustre; color pale copper-red; tarnishes gray
to black; powder pale brownish-black; brittle; on charcoal melts giving
the odor of garlic; becomes green in nitric acid; gravity 7.5.

VALUE.--An ore of nickel (containing forty-four per cent.) and arsenic.

LOCALITIES.--Found in granite regions. Chatham, Conn.


26.--COPPER PYRITES.

Occurs in crystals and masses; color brass-yellow; tarnishes green;
metallic lustre when freshly broken; can be cut with a knife; brittle;
powder greenish black; on charcoal melts giving off sulphur fumes;
dissolves in nitric acid, making a green liquid; gravity 4.2.

VALUE.--If of a fine yellow hue, it is a valuable copper ore (yielding
from twelve to forty per cent.) and source of blue vitriol.

LOCALITIES.--Found in mountainous or granite regions with other ores.
Lubec and Dexter, Me.; Franconia, Unity, Warren, Eaton, Lyme, Haverhill
and Shelburne, N. H.; Corinth, Waterbury and Strafford, Vt.;
Southampton, Turner’s Falls, Hatfield and Sterling, Mass.; Bristol and
Middletown, Conn.; Ancram, Rossie, Wurtzboro’ and Ellenville, N. Y.;
Phœnixville and Pottstown, Pa.; Bare Hills, Catoctin Mountains, near
Newmarket and Finksbury, Md.; Phœnix and Walton Mines, Va.;
Greensboro, Charlotte and Phœnix Mines, N. C.; Hiwassee Mines, Tenn;
Cherokee, Rabun and Habersham Counties, Ga.; Presque Island, Lake
Superior; Mineral Point, Wis.; Union, Keystone, Empire and other mines,
Calaveras County, La Victoire and Haskell claims in Mariposa County,
Amador and Plumas Counties, Cal.; near Virginia City, Mont.

[Illustration: PROSPECTING DIAMOND DRILL.]


27.--DIAMOND.

Occurs in crystals and irregular angular masses; cannot be scratched by
any other mineral or the file; brilliant lustre; feels cold to the
touch; when rubbed on the sleeve exhibits electricity for hours; retains
the breath but a short time; often tinged yellow, red, or green; gravity
3.5.

VALUE.--Used for jewelry, lenses and for cutting glass.

LOCALITIES.--Found in gold-regions, in river-washings of sand and
pebbles; usually with coarse gold, but deeper down. Rutherford,
Cabarras, Franklin and Lincoln Counties, N. C.; Hall County, Ga.;
Manchester, Va.; Cherokee Ravine, N. San Juan, French Canal, Forrest
Hill, Placerville and Fiddletown, Cal.


28.--EMERY.

Occurs in granular masses, sometimes with bluish crystals; looks like
fine grained iron ore; breaks with uneven surface; scratches quartz
easily; very tough; brittle; gravity 4.

VALUE.--Used extensively as a cutting and polishing material.

LOCALITIES.--Found generally in limestone or granite with _Magnetic Iron
Ore_. Chester, Mass.; Newlin and Unionville, Penn.; Macon and Guilford
Counties, N. C.


29.--FLUOR SPAR.

Occurs in square crystals and in masses; glassy lustre; powder white;
brittle; crackles when heated and then shines in the dark; does not
effervesce with acids; is not scratched by marble; gravity 3.

VALUE.--Used as flux in glass and iron works.

LOCALITIES.--Found in limestone, granite, slate, etc., often at
lead-mines. Blue Hill Bay, Me.; Westmoreland, N. H.; Putney, Vt.;
Southampton, Mass.; Trumbull, Plymouth, Middletown and Willimantic,
Conn.; Muscolonge Lake, Rossie and Johnsburg, N. Y.; near Franklin, N.
J.; near Woodstock and Shepardstown, Va.; Smith County, Tenn.; Mercer
County, Ky.; Gallatin County, along the Ohio, Ill. Castle Dome
District, Ariz.


30.--FRANKLINITE.

Occurs crystallized and in masses; generally made of coarse grains;
brittle; powder dark reddish-brown; heated with soda turns bluish-green;
dissolves in muriatic acid; gravity 5.

VALUE.--An ore of zinc.

LOCALITIES.--Found in limestone with _Garnet_ and _Zincite_. Hamburg and
Stirling Hill, N. J.


31.--GALENA.

Occurs in crystals and masses; brilliant lustre; brittle; easily broken;
powder, when finely rubbed is black; can be cut with a knife; heated it
gives off sulphur and melts; dissolves in nitric acid leaving a white
powder at the bottom; gravity 7.5--or a little heavier than cast-iron.

VALUE.--The main source of lead (yielding eighty per cent), and also
smelted for the silver it contains. Used also in glazing stone-ware.

LOCALITIES.--Generally found in limestone with _Iron Pyrites_, zinc-ore,
etc. That found in slate is richest in silver. Abounds in Missouri,
Illinois, Iowa, Wisconsin and Arkansas; Rossie, Wurtzboro, Ancram,
Macomb and Ellenville, N. Y.; Lubec, Blue Hill Bay, Bingham and
Parsonsville, Me.; Eaton, Shelburne, Haverill, Warren and Bath, N. H.;
Thetford, Vt.; Southampton, Leverett and Sterling, Mass.; Middletown and
Roxbury, Conn.; Phœnixville, Charlestown, Schuylkill, Pequea Valley
and Shannonville, Pa.; Austin’s and Walton’s Mines, Va.; Cabarras
County, N. C.; Brown’s Creek and Haysboro, Tenn.; Chocolate River,
Mich.; Ingo County, Cal.; on Walker’s River and Steamboat Springs, Nev.;
Castle Dome and Eureka, Ariz.; Clear Creek County, Col.; Virginia City
and Red Bluff Lode, Mont.; Cache Valley, Utah.


32.--GARNET.

Occurs in crystals with four-sided faces; often nearly round; deep red,
which grows darker by heat; rarely yellow; also in brown masses; melts
at a high heat; brittle; not scratched by a knife; glassy lustre;
gravity 4.

VALUE.--The clear deep red and yellow varieties are used for jewelry;
the massive brown is ground for “emery.”

LOCALITIES.--Found in slate and granite rocks. Bethel, Parsonsfield,
Phippsburg, Windham, Brunswick and Ranford, Me.; Hanover, Franconia,
Haverhill, Warren, Unity, Lisbon and Grafton, N. H.; New Fane, Cabot and
Cavendish, Vt.; Carlisle, Boxborough, Brookfield, Brimfield, Newbury,
Bedford, Chesterfield and Barre, Mass.; Reading, Monroe, Haddam and
Middletown, Conn.; Rogers’ Rock, Crown Point, Willsboro, Middletown,
Amity, and near Yonkers, N. Y.; Franklin, N. J.; Pennsbury, Warwick,
Aston, Knauertown, Chester, Leiperville and Mineral Hill, Pa.; Dickson’s
Quarry, Del.; Hope Valley, Cal.; near Virginia City, on Yellowstone and
Madison Rivers, Mont.


33.--GOLD.

Occurs in scales, grains and nuggets, or disseminated through cellular
quartz; metallic lustre; without tarnish; can be cut and hammered into
thin plates; not dissolved by nitric acid; gravity 19, when pure and of
a rich gold yellow color. The pale or brass yellow specimens are much
lighter, the gravity being as low as 13. A grayish yellow gold,
occurring in small, flat grains has a gravity of about 16.

LOCALITIES.--Found in veins of quartz running through greenish or
grayish slates, the quartz at the surface being generally full of
cavities and rusted, and the slates below the surface often containing
little cubic crystals of _Iron Pyrites_: also in the valleys traversed
by mountain-streams and in the river sands and gravel below. _Iron_ and
_Copper Pyrites_, _Galena_ and _Blende_ frequently contain gold. Masses
of quartz and pyrites from the gold-regions, which make no show of gold,
sometimes pay well; the value of such specimens can be

[Illustration: WASHING AURIFEROUS SANDS.]

determined only by an assayer. Eastern range of Appalachians, as
Habersham, Rabun, Clark, Hall, Lumpkin and Lincoln Counties, Ga.;
Abbeville, Chesterfield, Union, Lancaster and Pickens Counties, S. C.;
Montgomery, Cabarras, Mechlenburg, Burke and Lincoln Counties, N. C.;
Spotsylvania, Buckingham, Fauquier, Stafford, Culpepper, Orange,
Goochland and Louisa Counties, Va.; Dedham, Mass.; Bridgewater, Vt.;
Canaan and Lisbon, N. H.; on Sandy River and Madrid, Me. Numberless
points along the higher Rocky Mountains and western slope of Sierra
Nevada, as near Santa Fe, Cerillos and Avo, New Mex.; San Francisco,
Wauba and Yuma District, Ariz; between Long’s Peak and Pike’s Peak,
Col.; Comstock Lode, Nev.; Owyhee, Boise and Flint Districts and Poorman
Lode, Idaho; Emigrant and Alder Gulches, Red Bluff and near Jefferson
River, Mont.; Josephine District, Powder, Burnt, and John Day Rivers,
western slope of Cascade Mountains, and southern coast, Oregon; Tulare,
Fresno, Mariposa, Tuolumne, Calaveras, El Dorado, Placer, Nevada, Yuba,
Sierra, Butte, Plumas, Shasta, Siskiyou Amador and Del Norte Counties,
Cal. Rare in the coal-regions and Mississippi Valley.


34.--GRAPHITE.

Occurs in foliated, scaly and granular masses; can be cut into thin
slices, which are flexible, but not elastic; impressible by the nail;
feels greasy; leaves a shining trace on paper; metallic lustre; not
altered by heat or acids; gravity 2.

VALUE.--Used for pencils, polishing, glazing, for making steel,
crucibles, overcoming friction, etc.

LOCALITIES.--Found in granite, slate and limestone rocks. Sturbridge,
North Brookfield, Brimfield, Hinsdale and Worthington, Mass.; Cornwall
and Ashford, Conn.; Brandon, Vt.; Woodstock, Me.; Goshen, Hillsboro and
Keene, N. H.; Ticonderoga, Fishkill, Roger’s Rock, Johnsburg, Fort Ann,
Amity, Rossie and Alexandria, N. Y.; Franklin and Lockwood, N. J.;
Southampton and Buck’s County, Penn.; on the Gunpowder, Md.; Albemarle
County, Va.; Wake, N. C.; Tiger River and Spartanburgh, S. C.; Sonora,
Cal. (The soft black slate, often mistaken for _Graphite_, leaves a
coaly trace on paper not a shining streak.)


35.--GRAY COPPER ORE.

Occurs in crystallized or granular masses; metallic lustre; color
between steel-gray and iron-black; brittle; the powder dissolved in
nitric acid makes a brownish green solution; melts at a red heat;
gravity 5.

VALUE.--An ore of copper, (containing thirty-three per cent.) and
silver, of which Nevada specimens have sixteen per cent.

LOCALITIES.--Found with gold, silver and lead. Kellogg Mines, Ark.;
Mariposa and Shasta Counties, Cal.; Sheba and De Soto Mines, and near
Austin, Nev.; Heintzelman and Santa Rita Mines, Arizona.


36.--GYPSUM.

Occurs in plates, fibres coarse and fine, and massive; pearly or
glistening; powder white, which if heated and mixed with water, turns
hard; does not dissolve in sulphuric acid; may be scratched by the nail;
gravity 2.3.

VALUE.--Used for stucco, manure, glazing, statuary, manufacture of
glass, etc. A variety, called _Satin Spar_, worked into necklace beads
and other ornaments, is finely fibrous and compact, taking a polish
(though easily scratched,) and then resembles pearl or opal.

LOCALITIES.--Found with marl or clay, limestone and salt. Camillus,
Manlius, Stark and Lockport, N. Y.; on the St. Mary’s and Patuxent, Md.;
Washington County and Lynchburg, Va.; Charleston, S. C.; Poland, Ottawa
and Canfield, O.; Davidson and Summer Counties, Tenn.; Grand Rapids and
Sagenaw Bay, Mich.; Des Moines River, Iowa; Walker Lake and Six Mile
Cañon, Nev.; Fort Dodge.


37.--HORN SILVER.

Occurs in crystals, wax-like masses, or in crusts; when scratched shows
a shining streak; becomes brown on exposure; quite soft, easily cut; a
small piece placed on zinc and moistened, swells up, turns black and
shows metallic silver on being pressed with a knife; dissolves in
hartshorn; gravity 5.5.

VALUE.--An ore of silver, yielding seventy per cent.

LOCALITIES.-Found in slate with other silver ores. Lake Superior Mining
Region; Austin and Comstock Lode, Nev.; Willow Springs and San Francisco
districts, Eldorado Cañon, Ariz.; Poorman Mine, Idaho.


38.--IRON PYRITES.

Occurs in masses and square crystals; splendent lustre; color,
bronze-yellow; brittle; strikes fire with steel; heated it gives off
sulphur fumes; powder brownish; gravity 5.

VALUE.--Affords sulphur, copperas and alum. When found outside of the
coal region, it often contains gold and silver.

LOCALITIES.--Found in all kinds of rocks. Bingham, Corinna, Farmington,
Waterville, Brooksville, Peru and Jewett’s Island, Me.; Shelburne, Unity
and Warren, N. H.; Baltimore, Hartford and Shoreham, Vt.; Heath,
Hubbardston and Hawley, Mass.; Roxbury, Monroe, Orange, Milford,
Middletown, Stafford, Colchester, Ashford, Tolland and Union, Conn.;
Rossie, Malone, Phillips, Johnsburgh, Canton, Chester, Warwick and
Franklin, Putnam and Orange Counties, N. Y.; Chester, Knauertown,
Cornwall and Pottstown, Pa.; Greensboro’, N. C.; Mercer County, Ky.;
Bainbridge, O.; Galena at Marsden’s Diggings, Ill.; on Sugar Creek,
Ind.; mines of Colorado and California.


39.--JASPER.

Occurs in masses, either in veins or as rounded stones; dull lustre, yet
takes a high polish; breaks with a curved surface; not attacked by
acids; is scratched by _Rock Crystal_; gravity 2.5.

VALUE.--Used for mosaics and other ornaments when compact, fine-grained
and bright color.

LOCALITIES.--Found everywhere. Sugar Loaf Mountain and Machiasport, Me.;
Saugus, Mass.; Castleton and Colchester, Vt.; Bloomingrove, N. Y.;
Murphy’s, Col.; Red Bluff, Mont.


40.--KAOLIN.

Occurs in beds; it is a fine, white clay, plastic when wet; when dry is
scaly or compact; can be crumbled in the fingers and feels gritty;
adheres to the tongue; does not dissolve in acids.

VALUE.--Used for the finest porcelain and for adulterating candy.

LOCALITIES.--Found generally with iron-ore and fire-clay. Common on the
eastern slope of the Alleghanies; Branford, Vt.; Beekman, Athol,
Johnsburgh and McIntyre, N. Y.; Perth Amboy, N. J.; Reading, Tamaqua and
New Garden, Penn.; Mt. Savage, Md.; Richmond, Va.; Newcastle and
Wilmington, Del.; Edgefield, S. C.; near Augusta, Ga.; Jacksonville,
Ala.


41.--LENTICULAR IRON ORE.

Occurs in beds or masses, consisting of minute flattened grains; little
lustre; generally soils the fingers; breathed upon has a clayey odor;
color, brownish-red, powder more red; dissolves in strong muriatic acid
with some effervescence; brittle; gravity 4.

VALUE.--An ore of iron yielding thirty-three per cent. Generally mixed
with other ores at the furnace.

LOCALITIES.--Found in sandstone. Wayne, Madison, Oneida and Herkimer
Counties, N. Y.; Marietta O.


42.--LIMONITE, OR BROWN HEMATITE.

Occurs in masses, with smooth rounded surfaces and fibrous structure;
sometimes as hollow nodules, which are velvety-black inside; its powder
when rubbed is yellowish-brown; when strongly heated turns black;
scratches glass feebly; brittle; dissolves in hot aqua-regia; gravity 4.

VALUE.--A common ore of pig-iron, containing sixty per cent.; used also
for polishing buttons, etc.

LOCALITIES.--Found in heavy beds with mica-slate, quartz, limestone,
etc. Salisbury and Kent, Conn.; Amenia, Fishkill, Dover and Beekman, N.
Y.; Richmond and Lenox, Mass.; Pittsfield, Putney, Bennington and
Ripton, Vt.; Hamburgh, N. J.; Pikeland and White Marsh, Penn.;
Marquette, Mich.; Makoquata River, Iowa; Iron Mountains, Stow and Green
Counties, Mo.; Centerville, Ala.; near Raleigh and Smithfield, N. C.; on
Coal Creek, Col.; and in coal areas generally.


43.--MAGNETIC IRON ORE.

Occurs in granular masses, coarse or fine; attracted by the magnet, or
affecting the compass-needle; powder black; brittle; dissolves in
muriatic acid; gravity 5.

VALUE.--An important ore, yielding sixty-five per cent.

LOCALITIES.--Found in granite, slate and limestone rocks. Warren, Essex,
Clinton, Saratoga, Herkimer, Orange and Putnam Counties, N. Y.; Raymond
and Marshall’s Island, Me.; Franconia, Jackson, Winchester, Lisbon,
Swanzey and Unity, N. H.; Bridgewater, Chittenden, Marlboro, Rochester,
Troy and Bethel, Vt.; Cambealon, R. I; Hawley and Bernardston, Mass.;
Haddam, Conn.; Goshen, Webb’s Mine, Cornwall and White Marsh, Penn.;
Hamburg, N. J.; Scott’s Mills and Deer Creek, Md.; Mitchell and Madison
Counties, N. C.; Spartanburg, S. C.; Laclede and Crawford Counties, Mo.;
Sierra County, (Gold Valley,) Plumas, Tulare, Mariposa, Placer and El
Dorado Counties, Cal.


44.--MAGNETIC PYRITES.

Occurs massive; brittle; deep orange-yellow; powder grayish-black;
metallic lustre; tarnishes easily; slightly attracts the
compass-needle; melts at a high heat, giving off sulphur-fumes; gravity
4.5.

VALUE.--Affords sulphur, copperas and nickel.

LOCALITIES.--Found in granite regions, often with copper and iron ores.
Stafford, Corinth and Shrewsbury, Vt.; Trumbull and Monroe, Conn.; Port
Henry, Diana and Orange County, N. Y.; Hurdstown, N. J.; Gap Mine,
Lancaster County, Pa.; Ducktown Mines, Tenn.


45.--MALACHITE.

Occurs in incrustations with smooth surface and fibrous; powder paler
green than the mineral; brittle; by heat crackles and turns black;
effervesces in acids; takes a fine polish, showing bands or rings;
gravity 4.

VALUE.--Used for jewelry and inlaid work.

LOCALITIES.--Found in copper and lead mines. Cheshire, Conn.; Brunswick
and Schuyler’s Mines, N. J.; Morgantown, Cornwall, near Nicholson’s Gap,
Perkiomen and Phœnixville Lead Mines, Pa.; Petapsco Mines, Md.;
Davidson County N. C.; Polk County, Tenn.; Left Hand River and Mineral
Point, Wis.; Falls of St. Croix, Minn.; Jefferson County and Mine la
Motte, Mo.; Calaveras County, Cal.; Big Williams’ Fork, Ariz.; Wild Cat
Cañon and near Virginia City, Mont.


46.--MANGANESE SPAR.

Occurs in masses; glassy lustre; color flesh or rose-red; becomes black
on exposure; tough; melted with borax gives a violet-blue color; gravity
3.5.

VALUE.--Used in glazing stone-ware.

LOCALITIES.--Found in granite regions, often with iron-ore. Blue Hill
Bay, Me.; Cummington, Warwick and Plainfield, Mass.; Irasburg and
Coventry, Vt.; Winchester, and Hinsdale, N. H.; Cumberland, R. I.;
Franklin and Hamburg, N. J.


47.--MARBLE.

Occurs coarse and fine granular; frequently veined or mottled; brittle;
can be cut with a knife; takes a polish; effervesces with acids;
reduced to quicklime by heat; a gray variety contains stems and joints
of worm-like fossils; gravity 2.5.

LOCALITIES.--Brandon, Rutland, Dorset, Shoreham, Pittsford, Middlebury,
Fairhaven, Cavendish, Lowell, Troy and Sudbury, Vt.; West Stockbridge,
Egremont, Great Barrington, Lanesboro, New Ashford, Sheffield, New
Marlboro, Adams, Cheshire and Stoneham, Mass.; Clinton, Essex, Dutchess,
Onondaga, Putnam, St. Lawrence, Warren and Westchester, Counties, N. Y.;
Smithfield, R. I.; New Haven, Milford, Conn.; near Philadelphia, N. J.;
Texas and Hagerstown, Md.; Lancaster County, Pa.; Jefferson and
Genevieve Counties, Mo.; Knox and Sevier Counties, Tenn.; Joliet, Ill.;
Cherokee and Macon Counties, N. C.; Marquette, Mich.; near Deep River
and on the Michigamig and Menominee Rivers, Wis.


48.--MICA.

Occurs in masses, which can be split into very thin, elastic leaves;
pearly lustre; at a high heat becomes opaque; gravity 3.

VALUE.--Used for doors of stoves, etc.

LOCALITIES.--Found in granite regions. Buckfield, Freeport and Oxford,
Me.; Acworth, Grafton and Alstead, N. H.; Chesterfield, Barre, Mendon,
South Royalston, Brimfield, Goshen and Russell, Mass.; Monroe, Haddam
and Middletown, Conn.; Warwick, Edenville, Edwards, Monroe and
Greenfield, N. Y.; Pennsbury, Thornbury, Unionville, Middletown and
Chestnut Hill, Pa.; Jones’ Falls, Md.


49.--MICACEOUS IRON ORE.

Resembles _Specular Iron Ore_, but consists of thin shining scales or
leaves; powder dark red; a thin flake is translucent, showing red light;
feels somewhat slippery.

VALUE.--Used as an ore of iron and for polishing.

LOCALITIES.--Hawley, Mass.; Piermont, N. H.; Ticonderoga, N. Y.;
Warwick, Penn.; Loudon County, Va.


50.--NITRE.

Occurs in thin crusts, delicate needles, or disseminated through the
loose earth in caves; glossy lustre; brittle; cool, saline taste;
crackles and burns brightly on live coals; a little harder than
_Gypsum_.

VALUE.--Used in the manufacture of gunpowder, fulminating powders,
nitric acid, etc.

LOCALITIES.--Marion County, Ky.; White County, Tenn.; near Rosiclare,
Ill.; Silver Peak, Nev.


51.--OXYD OF MANGANESE.

Occurs in masses and little columns, often with small rounded surfaces;
one ore is soft enough to be impressed by the nail, and soils; the other
will scratch glass faintly; heated with borax, makes a violet glass;
dissolves in hot muriatic acid, giving forth a yellowish-green gas;
gravity 4 to 5.

VALUE.--Used for bleaching and for obtaining oxygen.

LOCALITIES.--Found in granite regions, often with iron-ore. Brandon,
Bennington, Monkton, Irasburg and Chittenden, Vt.; Hillsdale,
Westmoreland and Westchester, N. H.; Plainfield, West Stockbridge and
Conway, Mass.; Salisbury and Kent, Conn.; Montgomery County, Md.; Lake
Superior Mining Region; Dubuque, Iowa; Deep Diggings, Mo.; Red Island,
Cal.; Martinsburg, N. Y.


52.--PLATINUM.

Occurs in grains or lumps; metallic, silvery lustre; can be hammered
out; heavier and harder than silver; not dissolved in nitric acid;
gravity 17.

VALUE.--Nearly equal to _Gold_. Used for making chemical and
philosophical apparatus, for coating copper, brass, etc.

LOCALITIES.--Found in river-gravel with _Gold_. Rutherford County, N.
C.; Klamath region, Cape Blanco, on Salmon River, South Fork of Trinity,
Butte, Honcut, Cañon and Wood’s Creeks, and on Middle Fork of American
River, Cal.; at Gold Flat, Nev.


53.--RED COPPER ORE.

Occurs in crystals and masses; cochineal-red; powder brownish-red;
nearly opaque; brittle; dissolves in nitric acid; heated on charcoal
yields a globule of copper; gravity 6.

VALUE.--Affords copper, (sixty per cent.,) and blue vitriol.

LOCALITIES.--Found in trap regions with other copper ores. Schuyler’s,
Somerville, New Brunswick and Flemington Mines, N. J.; Cornwall, Pa.;
Ladenton, N. Y.; Lake Superior Region. Not abundant.


54--RED HEMATITE.

Occurs in compact masses, with rounded surfaces or kidney-shaped;
fibrous structure; color brownish-red to iron-black; but powder
invariably red; when black, the lustre is somewhat metallic, otherwise
dull; brittle; scratches glass with difficulty; dissolves slowly in
strong muriatic acid; gravity 4.5 to 5.

VALUE.--An ore of iron, yielding from thirty-six to fifty per cent. In
powder, used as pigment and for polishing metals.

LOCALITIES.--Found usually in beds with granite or limestone. Aroostook
County and Hodgdon, Me.; Antwerp, Ticonderoga, Crown Point and
Gouverneur, N. Y.; Vernon, N. J.; West Whiteland, Pa.; Chatham and
Orange Counties, N. C.; Marquette, Mich; Shasta County, Cal. This
mineral graduates into a soft, earthy variety, called _red ochre_, and
into a compact, slaty variety, called _red chalk_, which has a clayey
odor when breathed on.


55.--RED SILVER ORE.

Occurs in crystals and masses; metallic lustre; brittle; powder
cochineal-red; easily cut; at a high heat yields a silver globule; the
powder heated with potash turns black; gravity 6.

VALUE.--An ore of silver yielding sixty per cent.

LOCALITIES.--Found at gold and silver mines. Washoe and Austin, Nev.;
Poorman Lode, Idaho.


56.--RENSSELAERITE.

Occurs in masses; wax-like; a trifle harder than marble; when fresh can
be scratched by the nail; soapy feel; takes a polish; cleavable; gravity
2.8.

VALUE.--Used as a marble and worked into inkstands, etc.

LOCALITIES.--Found with _steatite_, _serpentine_, limestone, etc.
Antwerp, Canton, Fowler, De Kalb, Edwards, Russell and Gouverneur, N. Y.


57.--ROCK CRYSTAL.

Occurs in crystals and masses; transparent; glassy lustre; colorless;
tough; brittle; not acted upon by acids or heat; electric by friction;
gravity 2.5.

VALUE.--Cut for ornaments, lenses, etc.

LOCALITIES.--Common in sandstone, limestone and iron ore. Paris, Me.;
Benton and Bartlett, N. H.; Sharon and Woodstock, Vt.; Pelham and
Chesterfield, Mass.; Ellenville, Little Falls, Watervliet, Fairfield,
Middleville, Fowler, Antwerp, Rossie, Lake George and Palatine, N. Y.;
Minnesota Mine, Lake Superior; Ouachita Spring, Ark.


58.--ROCK SALT.

Occurs in irregular beds or masses; brittle; saline taste; crackles in
the fire.

LOCALITIES.--Found with _gypsum_, clay and sandstone. Washington County,
Va.; Petit Anse, La.; Silver Peak, Nev.; Salmon River Mountains, Oregon.


59.--RUTILE.

Occurs in crystals generally; metallic lustre; powder pale brown;
brittle; unchanged by heat or acids; if powdered and fused with potash,
then dissolved in muriatic acid, the solution boiled with tinfoil
assumes a beautiful violet color; gravity 4.

VALUE.--Used for coloring porcelain and artificial teeth.

LOCALITIES.--Found in granite and, limestone rocks. Warren, Me.;
Merrimack, and Warren, N. H.; Bristol, Putney and Waterbury, Vt.;
Windsor, Shelburne, Barre, Conway and Leyden, Mass.; Monroe, Conn.;
Warwick, Edenville, Amity and Kingsbridge, N. Y.; Sudsbury, West
Bradford, Parksburg, Concord and Newlin, Pa.; Newton, N. J.; Crowder’s
and Clubb Mountains, N. C.; Habersham and Lincoln Counties, Ga.; Magnet
Cave, Ark.


60.--SERPENTINE.

Occurs in masses; feeble, resinous lustre; color oily green; powder
whitish; often yellowish gray on the outside; can be cut easily; takes a
fine polish; becomes reddish by heat; gravity 2.5--same as _Marble_.

VALUE.--Worked into mantels, jambs, table-tops, and many other
ornaments.

LOCALITIES.--Found as a rock in large masses. Deer Isle, Me.; Baltimore,
Cavendish, Jay and Troy, Vt.; Newbury, Blanford, Middlefield and
Westfield, Mass.; Newport, R. I.; near New Haven and Milford, Conn.;
Port Henry, Antwerp, Syracuse, Warwick, Phillipstown, Canton,
Gouverneur, Johnsburg, Davenport’s Neck, New Rochelle and Rye, N. Y.;
Frankford, Hoboken and Montville, N. J.; Texas, Pa.; Cooptown, Md.;
Patterson, N. C.; Calaveras County, Cal.; Alder Gulch, Mont. Marble
veined with serpentine is called _verd-antique_.


61.--SILICATE OF COPPER.

Occurs in incrustations and masses; color bluish-green; not fibrous;
surface smooth; easily cut; does not effervesce in acid; blackens by
heat; gravity 2.

VALUE.--An ore of copper, yielding thirty per cent.

LOCALITIES.--Found with other copper ores. Somerville and Schuyler’s, N.
J.; Morgantown and Cornwall, Pa.; Wolcottville, Conn.; Big Williams’
Fork, Ariz.


62.--SILVER.

Occurs in masses, or strings and threads penetrating rocks and native
copper and galena; metallic lustre; tarnishes grayish black; can be cut
in slices and hammered out; dissolved in muriatic acid, it turns black
on exposure; gravity 10.

LOCALITIES.--Chiefly found with copper near trap-rocks, and in fine
grained _galena_ and dark brown _blende_. _Gold_ contains from one to
fifteen per cent. Bridgewater, N. J.; Davidson and Stanley Counties, N.
C.; Lake Superior Region; Poorman’s Lode, Idaho; Comstock Lode and
Montezuma Ledge, Nev.; Alpine County and Maris Vein, Cal.; Clear Creek
County, Col.


63.--SILVER GLANCE.

Occurs in small lumps, plates and threads; color dark gray; cuts like
lead; melts in a candle giving off sulphur fumes; gravity 7.

VALUE.--The most important ore of silver, containing eighty-seven per
cent.

LOCALITIES.--May be found almost everywhere, except in the coal regions;
associated with other ores, quartz, limestone, baryta, etc. Most
abundant where mineral veins cross one another. Comstock Lode, Gold
Hill, Reese River, Cortez District and Silver-Sprout Vein, Nev.; Clear
Creek County, Nev.


64.--SMALTINE.

Occurs in crystals and masses; metallic lustre; color tin-white to
steel-gray; powder dark gray; brittle; gives off garlic odor in a
candle; melted with borax makes a deep blue glass; gravity 6.5 to 7.

VALUE.--An ore of cobalt and arsenic, containing eighteen to seventy per
cent.

LOCALITIES.--Found in veins in granite regions with other ores, Mine la
Motte, Mo.; Chatham, Conn.


65.--SMITHSONITE.

Occurs in masses, often rounded, covered with minute crystals, or
honeycombed; color white, dirty yellow or stone color; glassy lustre;
brittle; effervesces in nitric acid; barely scratches glass; barely
translucent; gravity 4.4.

VALUE.--Yields fifty per cent. of zinc.

LOCALITIES.--Found generally in limestone with _galena_ and _blende_.
Friedenville, Lancaster and Perkiomen, Pa.; Linden and Mineral Points,
Wis.; Lawrence, County, Ark.; Ewing’s Diggings, Minn.


66.--SPATHIC IRON.

Occurs in crystals or plates somewhat curving; also (in coal regions) in
nodules with concentric layers like an onion; brittle; color varies from
white to yellowish-brown or dark-brown; strongly heated it blackens and
will then attract the compass needle; the powder effervesces in nitric
acid; melted with borax makes a green or yellow glass; gravity 3.8.

VALUE.--Yields thirty per cent. of iron, well adapted for steel.

LOCALITIES.--Found in granite and coal-formations, often with other
ores. Plymouth, Vt.; Sterling, Mass.; Roxbury, Conn.; Antwerp, Herman
and Rossie, N. Y.; Fentress and Harlem Mines, N. C.; Coal Regions of
Western Pa., Virginia, Eastern Ohio, etc.


67.--SPECULAR IRON ORE.

Occurs crystallized and in large masses, high metallic lustre; color
steel-gray or iron-black; brittle; opaque except when very thin; the
powder when very fine and rubbed on white paper shows red; the powder
dissolves slowly in muriatic acid; by a strong heat yields a black mass
which attracts the needle; gravity 5.

VALUE.--Yields from fifty to seventy per cent. of iron.

LOCALITIES.--Found in granite regions. Marquette, Mich.; Pilot Knob and
Iron Mountains, Mo.; St. Lawrence County, N. Y.; Bartlett, Lisbon and
Franconia, N. H.; Chittenden and Weathersfield, Vt.; Sauk County, Wis.


68.--SPINEL RUBY.

Occurs in pyramidal crystals; glassy lustre; powder white; scratches
_rock-crystal_; by heat becomes black; gravity 3.5.

VALUE.--A gem; clear specimens weighing over four carats, are valued at
half the price of the _diamond_.

LOCALITIES.--Found in granular limestone and clay. Amity and Gouverneur,
N. Y.; Franklin and Byram, N. J.; Bolton and Boxborough, Mass.


69.--STEATITE.

Occurs in masses, consisting of minute pearly scales or grains; can be
marked by the nail; hardens by heat; soapy feel; gravity 2.5.

VALUE.--Used for fire-stones, tubes, in manufacture of porcelain, etc.

LOCALITIES.--Found in beds with limestone, serpentine and slate. Orr’s
Island, Me.; Francestown, Keene, Orford and Pelham, N. H.; Athens,
Cavendish, Marlboro, Moreton, New Fane, Bradboro, Troy, Waterville,
Westfield, Weathersfield and Windham, Vt.; Middlefield, Lenox and
Westfield, Mass.; Manayunk and Chestnut Hill, Pa.; Albemarle and Loudon
Counties, Va.; Staten Island and St. Lawrence County, N. Y.; Bare Hills,
Md.


70.--STRONTIANITE.

Occurs in crystals and in fibrous or granular masses; glassy lustre;
brittle; thin pieces melt before a blow-pipe tinging the flame red;
effervesces with acids; gravity 3.6.

VALUE.--A source of nitrate of strontia used in fire-works.

LOCALITIES.--Found in limestone. Schoharie, Muscalonge Lake, Chaumont
Bay and Theresa, N. Y.


71.--SULPHUR.

Occurs in crystals, masses and crusts; brittle; can be easily cut; burns
with a blue flame and sulphur odor; gravity 2.

LOCALITIES.--Found in limestone and gypsum, and around geysers and
sulphur springs. Springport, N. Y.; on the Potomac, twenty-five miles
above Washington; Put-in-Bay Island, Lake Erie; Clear Lake, Cal.; Santa
Barbara County, Col.; Humboldt County, Nev.


72.--TIN ORE.

Occurs in crystals, grains and masses; high lustre; powder gray or
brownish; brittle; will strike fire with steel; unaltered by heat or
acids; gravity 7,--being nearly as heavy as lead-ore.

VALUE.--The only ore of tin, containing seventy-nine per cent. No
gold-mine ever paid such profits as the tin mines of Cornwall.

LOCALITIES.--Jackson, N. H.; Temescal, Cal.; Boonville, Idaho; near
Fredericktown, Mo.


73.--TOPAZ.

Occurs in crystals; glassy lustre; brittle; scratches _rock-crystal_;
not acted upon by ordinary heat or acids; gravity 3.5.

VALUE.--A gem; the most esteemed are the rose-red and white.

LOCALITIES.--Found in granite. Trumbull, Willimantic and Middletown,
Conn.; Crowder’s Mountain, N. C.; Thomas’s Mountains, Utah.


74.--TOURMALINE.

Occurs in crystals, usually in long, slender three-sided prisms which
break easily, glassy lustre; brittle; becomes milk-white by heat;
scratches _rock-crystal_ and _garnet_; gravity 3.

VALUE.--Used for jewelry.

LOCALITIES.--Found in granite rocks. Paris, Albany and Hebron, Me.;
Chesterfield and Goshen, Mass.; Newlin and Marple, Pa.


75.--VARIEGATED COPPER ORE.

Occurs in crystals and masses; metallic lustre; quickly tarnishes; color
between copper-red and light-brown; powder pale grayish-black; dissolves
in nitric acid; at a high heat melts to a copper globule; heated on
charcoal gives off fumes of sulphur; gravity 5.

VALUE.--An important ore of copper yielding sixty per cent.

LOCALITIES.--Found in granite, freestone, etc., with other ores. Bristol
and Cheshire, Conn.; Mahoopeny, Pa.; Copper Mines of N. J.


76.--WAD.

Occurs in masses; earthy and loose; can be broken by the fingers, and
soils; no lustre; melted with borax makes a violet glass; feels very
light.

VALUE.--Used in bleaching and for making smalt.

LOCALITIES.--Found in low places, generally in the vicinity of slate or
iron ore beds. Warren, Vt.; Blue Hill, Hodgdon and Thomaston, Me.;
Columbia and Duchess Counties, Austerlitz, Canaan Centre and
Martinsburg, N. Y.; East Bradford and White Marsh, Pa.; Mine la Motte,
Mo.


77.--WILLEMITE.

Occurs in crystals and masses; feeble lustre; brittle; can hardly be cut
with a knife; sometimes scratches glass; makes a jelly in muriatic acid;
gravity 4.

VALUE.--Contains seventy per cent. of zinc.

LOCALITIES.--Found in limestone with _zincite_. Franklin and Sterling,
N. J.


78.--ZINCITE.

Occurs in foliated masses or grains, powder orange-yellow; brittle;
dissolves in acids without effervescence; gravity 5.5.

VALUE.--Yields seventy-five per cent. of zinc.

LOCALITIES.--Found in limestone with _Franklinite_, _Garnet_, etc.
Sterling Hill and Mine Hill, N. J.

[Illustration: decorative image]




CHAPTER IV.

PROSPECTING FOR DIAMONDS, GOLD, SILVER, COPPER, LEAD AND IRON.

     MINERAL RICHES, HOW DISCOVERED--INDICATIONS--SEARCHING FOR
     DIAMONDS, AND HOW TO DISTINGUISH THEM--PAYING LOCALITIES OF
     GOLD--“FOOL’S GOLD”--PROSPECTING FOR SILVER AND COPPER--WHERE TO
     LOOK FOR LEAD AND IRON.


The mineral riches of a country are frequently discovered by attentively
observing the fragments brought down by the action of water from the
hills into the valleys; and on tracing these to their several sources,
the veins from which they were originally detached, are in many
instances found. Water also acts in another way a very important part in
the discovery of mineral veins, as by closely examining the faces of the
different gullies and ravines, which intersect a country, a ready means
is afforded of ascertaining whether its strata are traversed by
metalliferous deposits; and, therefore, in exploring with a view to its
mineral productions, no opportunity should be lost of observing the
various sections thus naturally laid bare.

When fragments of an ore are found on a hill-side, it is very evident
that the vein must lie higher up. If the vein is horizontal and the
fragments are found on the top of the hill, there is no probability of
finding much if any of the vein, for generally it has been washed away.
Ore-veins, however, are almost always nearly vertical; so that boring is
of little use, as it might pass by the richest vein, or, striking it
lengthwise, give a too favorable result.

As heavy minerals do not drift far, metals are always found near their
source.

Horizontal beds can be worked at the least cost.

Pockets and nodules, or any detached masses of minerals, are soon
exhausted. Veins, lodes and beds are most valuable.

Boring a three-inch hole, which costs about $1 a foot, is a good method
of testing a mineral vein or bed which lies more or less horizontally. A
shaft may be sunk in sandstone for from $6 to $3 per cubic yard; in
slate and gravel, at from $2 to $1.

The existence of mineral springs, and the rapid melting of the snow in
any locality, are no indications of ores.

SEARCHING FOR DIAMONDS.--Few things are so unpromising and unattractive
as gems in their native state. Hence their slow discovery. There is
little doubt that diamonds exist in many places as yet unknown, or where
their presence is unsuspected. It is very difficult for the unpracticed
eye to distinguish them from crystals of quartz or topaz. The color
constitutes the main difficulty in detecting their presence. They are of
various shades of yellowish brown, green, blue and rose-red, and thus
closely resemble the common gravel by which they are surrounded. Often
they are not unlike a lump of gum arabic, neither brilliant nor
transparent. The finest, however, are colorless, and appear like
rock-crystals.

In Brazil, where great numbers of diamonds, chiefly of small size, have
been discovered, the method of searching for them is to wash the sand of
certain rivers in a manner precisely similar to that employed in the
gold fields, namely, by prospecting pans. A shovelful of earth is thrown
into the pan, which is then immersed in water, and gently moved about.
As the washing goes on, the pebbles, dirt and sand are removed, and the
pan then contains about a pint of thin mud. Great caution is now
observed, and ultimately there remains only a small quantity of sand.
The diamonds and particles of gold, if present, sink to the bottom,
being heavier, and are selected and removed by the practiced fingers of
the operator. But how shall the gems be detected by one who has had no
experience, and who in a jeweler’s shop could not separate them from
quartz or French paste? The difficulty can only be overcome by testing
such stones as may be suspected to be precious. Let these be tried by
the very sure operation of attempting to cut with their sharp corners
glass, crystal or quartz. When too minute to be held between the finger
and thumb, the specimens may be pressed into the end of a stick of hard
wood and run along the surface of window glass. A diamond will make its
mark, and cause, too, a ready fracture in the line over which it has
traveled. It will also easily scratch rock-crystal, as no other crystal
will.

But a more certain and peculiar characteristic of the diamond lies in
the form of its crystals. The ruby and topaz will scratch quartz, but no
mineral which will scratch quartz has the _curved edges_ of the diamond.
In small crystals this peculiarity can be seen only by means of a
magnifying glass; but it is invariably present. Interrupted, convex or
rounded angles, are sure indications of genuineness. Quartz crystal is
surrounded by six faces; the diamond by four. The diamond breaks with
difficulty; and hence a test sometimes used is to place the specimen
between two hard bodies, as a couple of coins, and force them together
with the hands. Such a pressure will crush a particle of quartz, but the
diamond will only indent the metal.

The value of the diamond is estimated by the carat, which is equal to
about four grains, and the value increases rapidly with its weight. If a
small, rough diamond weigh four grains, its value is about $10; if eight
grains, $40; if sixteen grains, $640. A cut diamond of one carat is
worth from $50 to $100.

The imperfections of the diamond, and, in fact, of all cut gems, are
made visible by putting them into oil of cassia, when the slightest flaw
will be seen.

A diamond weighing ten carats is “princely;” but not one in ten thousand
weighs so much.

If a rough diamond resemble a drop of clear spring water, in the middle
of which you perceive a strong light; or if it has a rough coat, so that
you can hardly see through it, but white, and as if made rough by art,
yet clear of flaws or veins; or, if the coat be smooth and bright, with
a tincture of green in it,--it is a good stone. If it has a milky cast,
or a yellowish-green coat, beware of it. Rough diamonds with a greenish
crust are the most limpid when cut.

Diamonds are found in loose pebbly earth, along with gold, a little way
below the surface, towards the lower outlet of broad valleys, rather
than upon the ridges of the adjoining hills.

SEARCHING FOR GOLD.--The paying localities of gold deposits are the
slopes of the Rocky and Alleghany Mountains. Gold need not be looked for
in the anthracite and bituminous coal-fields nor in limestone rock. It
is seldom found in the beds of rivers. The thing itself is the surest
indication of its existence. If soil or sand is “washed” as described in
Chapter V., and the particles of gold are not heavy enough to remain at
the bottom but float away, the bed will not pay.

Along streams rather high up among the mountains, and in the gravelly
drift covering the slopes of the valley below, are the best prospects.
Where the stream meets an obstacle in its path or makes a bend or has
deep holes, there we may look for “pockets” of gold. Black or red sands
are usually richest. Gold-bearing rock is a slate or granite abounding
in rusty looking quartz veins, the latter containing iron pyrites or
cavities. Almost all iron pyrites and silver ores, may be worked for
gold. When the quartz veins are thin and numerous rather than massive,
and lie near the surface, they are considered most profitable. Few veins
can be worked with profit very far down. As traces of gold may be found
almost everywhere, no one should indulge in speculation before
calculating the percentage and the cost of extraction. Gold-hunting,
after all, is a lottery with more blanks than prizes.

The substances most frequently mistaken for gold are _iron pyrites_,
_copper pyrites_ and _mica_. The precious metal is easily distinguished
from these by its malleability (flattening under the hammer) and its
great weight, sinking rapidly in water.

SEARCHING FOR SILVER.--This metal is usually found with lead ore and
native copper. Slates and sandstones intersected by igneous rocks as
trap and porphyry, are good localities. Pure silver is often found in or
near iron ores and the dark brown zinc blende. The Colorado silver lodes
are porous at the surface and colored more or less red or green. Any
rock suspected of containing silver should be powdered and dissolved in
nitric acid. Pour off the liquid and add to it a solution of salt. If a
white powder falls to the bottom which upon exposure turns black, there
is silver in it. Silver mines increase in value as in depth, whereas
gold diminishes as we descend.

SEARCHING FOR COPPER.--The copper ores, after exposure, or after being
dipped in vinegar, are almost invariably green on the surface. They are
most abundant near trap dykes. The pyrites is generally found in lead
mines, and in granite and clay-slate. Copper very rarely occurs in the
new formations, as along the Atlantic and Gulf borders, and in the
Mississippi Valley south of Cairo.

SEARCHING FOR LEAD.--Lead is seldom discovered in the surface soil. It
is also in vain to look for it in the coal region and along the coast.
It must be sought in steep hills, in limestone and slate rocks. A
surface cut by frequent ravines or covered by vegetation in lines,
indicates mineral crevices. The galena from the slate is said to
contain more silver than that from the limestone. The purest specimens
of galena are poorest in silver; the small veins are richest in the more
precious metal. A lead vein is thickest in limestone, thinner in
sandstone and thinnest in slate.

SEARCHING FOR IRON.--Any heavy mineral of a black, brown, red or yellow
color may be suspected to be iron. To prove it, dissolve some in oil of
vitriol and pour in an infusion of nut-gall or oak-bark; if it turns
black, iron is present. If a ton of rich magnetic ore costs more than $4
at the furnace, good hematite more than $3, and poor ores more than
$1.50 or $2, they are too expensive to pay, unless iron is unusually
high. Deep mining for iron is not profitable. Generally speaking, a bed
of good iron ore, a foot thick, will repay the cost of stripping it of
soil, etc., twelve feet thick. Red and yellow earths, called ochres,
contain iron. Magnetic ore is easily found by a compass.




CHAPTER V.

ASSAY OF ORES.

     WHEN AN ORE WILL PAY--WASHING FOR GOLD AND PLATINUM--HOW TO ASSAY
     GOLD IN THE SIMPLEST WAY--TO TEST ANY ROCK FOR GOLD AND SILVER--TO
     FIND THE PURITY OF GOLD--TO DETECT AND ASSAY SILVER ORES--ASSAY OF
     COPPER, IRON, ZINC, TIN AND LEAD ORES--READY METHOD OF TESTING
     GRAPHITE.


One of the first questions asked after the discovery of a metallic ore,
is--“will it pay?” We propose to state in plain words a method of
determining the character and value of the principal ores, so that any
intelligent man, however unscientific, may answer his own question. The
chemical analysis or exact assaying of ores is too complicated, and must
be left to professional assayers.

“Will it pay?” is an important query; for many ores of even precious
metals, are not “paying.” Whether an ore is profitable depends not so
much upon the relative value of the metal as upon the ease of separating
it from the rock or “gangue” as it is called. Thus the minimum
percentage of metal, below which the working of the ore ceases to be
profitable is--

Of Iron,        25         per cent.
   Zinc,        20             “
   Lead,        20             “
   Antimony,    20             “
   Copper,      02             “
   Tin,         01½         “
   Quicksilver, 01             “
   Silver,        1/2000       “
   Platinum,      1/10000      “
   Gold,          1/100000     “

That is, an ore of iron which contains less than 25 per cent. of metal
will not pay for working; for the reduction of iron in comparison with
copper ore is very difficult. Gold is very easily extracted, and hence
some quartz rocks which do not apparently contain a particle of gold,
pay well, a bushel of rock often yielding half an ounce.

Iron occurs in large masses or beds; but the other metals are scattered
in fragments through sand or soil, or exist in veins running through
rocks.

WASHING FOR GOLD AND PLATINUM.--This operation, called “panning,” is the
oldest and simplest method of extracting the precious metals. At the
present time, it furnishes to Russia nearly all the gold produced in
that empire. It is based on the principle that substances of different
weights may be separated by means of water,--the heaviest going to the
bottom first. To examine the bank or bed of a river, suspected to
contain gold, fill a milk-pan with the sands and carry it to a tub or
pool of quiet water. Dip it under, stirring the mass with one hand or a
stick. Then pour off the muddy water, fill with fresh water stirring
again, and again pour off the light sand, clay, etc. Scales of gold will
sink fast; mica flakes will take their time. Repeat this process till
all the fine particles are washed off; then allow just enough water to
enter the pan as will cover the sand. By shaking the pan and gradually
lowering the side by which it is held, the light sand will flow off,
leaving in the corner a heap of coarse sand. Put in a small quantity of
water and turn the pan around so as to create a gentle current, when the
precious metal, if there be any, can be easily detected,--the gold by
its bright lustre, the platinum by its lead color, and both by their
malleability. Particles of gold are of uniform color and are either flat
or rounded; while other yellow grains are angular. Holding the pan in
the sunshine, secure any glittering glassy crystals, and test them for
diamonds or rock-crystals. A magnet will remove any particles of
magnetic iron-ore.

ASSAY OF GOLD ORE.--Gold may be found in quartz rock, in iron and copper
pyrites, and in silver ores.

To ascertain if any gold is present in quartz, reduce the rock to
powder and sift it. A certain quantity, say half a peck, is then washed
as above described, till a manageable quantity of sand is left. If there
is any show of gold, dry the mass and put it in a bowl or glass dish,
and add an ounce of quicksilver, stirring the mixture well with a wooden
rod. The quicksilver, which will unite with every particle of gold which
may be there, is then poured off into a soft leather (chamois) bag. This
is squeezed to remove superfluous quicksilver, and a pasty amalgam is
left, which is put into an iron vessel and heated red hot. The yellow
powder remaining is mixed with saltpetre and melted, when a button of
pure gold will be found in the crucible. Quartz ores should yield $6 to
the ton in order to pay.

To test pyrites for gold, reduce a given quantity to powder and wash as
before; then roast the residue at a red heat. Upon cooling, add
quicksilver and treat as just described. Pyrites should yield $1 of
gold to the bushel of ore to be profitable.

Native silver often contains gold. To separate them, carefully flatten
the alloy with a smooth hammer on an anvil, and then boil it in strong
nitric acid in a glass flask for about ten minutes. Carefully pour off
the acid into a vial, and wash the powder in the flask (which is fine
gold) with water and dry. To the liquid in the vial add a solution of
common salt. The white powder which falls should be removed, washed with
water, and fused with powdered chalk or iron filings; a button of pure
silver is the result.

Any substance supposed to be or to contain gold may be tested by
dissolving it powdered in aqua regia and then pouring in a solution of
copperas; if there is gold, the reddish-brown precipitate, by rubbing,
assumes a bright metallic lustre.

To tell whether a globule of silver has any gold in it, put it on a
white porcelain dish and moisten it with a drop of nitric acid: if it
is pure silver, it will dissolve and retain its white color; if mixed
with gold, it will soon turn gray or black.

To test the purity of gold, rub some of it off on a hard black flint
slate, and apply to the mark a drop of aqua fortis. If the gold is pure,
the yellow streak remains unchanged, but if alloyed it partly
disappears; if it is only an imitation of gold, it vanishes altogether.

A ready method of finding the amount of gold in a quartz rock with
considerable accuracy, is by taking the specific gravity of the rock
(well cleaned) as given on page 13. If the gravity is not over 2.7, it
contains little or no gold. If it is 3, it very likely is gold-bearing,
although pyrites may be present. But if it is over 5, it is undoubtedly
auriferous, and if 12, it is very rich in gold.

It is generally considered that the sand of any river is worth working
for the gold it contains, provided it will yield twenty-four grains to
the hundred weight.

ASSAY OF SILVER ORE.--Pure silver is easily recognized. But lead and
copper ores often contain a large percentage of the precious metal.

To detect silver in lead ore, dissolve the powdered ore in strong nitric
acid; pour off the liquid and insert a piece of pure copper. If silver
is present, it will go to the bottom. Or, add to the liquid a solution
of common salt, and it will instantly become cloudy or white. If lead
ore yields three ounces of silver to a ton, it may be worked for the
silver as well as the lead. In Colorado, the average value of
silver-bearing galena is $100 per ton.

To test the copper ores for silver, dissolve them in nitric acid; then
add a few drops of muriatic acid, and if silver is present, a white
curdy precipitate will fall to the bottom. Native copper, when polished,
often shows white spots of silver.

To estimate the proportion of silver in lead ore, reduce a known
quantity of the clear ore to powder, mix with a little dry soda and a
few nails, and heat in a round-bottomed iron pot or crucible. The lead
which is obtained should then be put in a cup having ashes at the
bottom, and strongly heated in an open furnace. A globule of silver will
be left, if any is present, and being weighed, the percentage can be
found.

Rich silver ores may be reduced by mixing them with ten parts of common
salt, and exposing the mass for hours in an open furnace, stirring it
frequently. When cold reduce to powder and mix with an equal quantity of
quicksilver and enough water to make a paste, and agitate the mixture
for two days, when the amalgam will fall to the bottom. The amalgam is
then squeezed in a leather bag and washed.

Silver glance will yield its metal by heating it before a blow-pipe.

ASSAY OF COPPER ORE.--When the ore is native copper and rock, as at Lake
Superior, it should be pounded and the earthy matter washed away. Then
mix with a little potash or soda and bring to a high heat in a
crucible.

Other copper ores may be tested by dissolving them powdered in dilute
aqua regia. The presence of silver will be shown by a white powder on
the bottom. Then add considerable ammonia. If there is any copper a blue
liquor will be produced. Strain this through tissue paper, and evaporate
to dryness. Dissolve the residue in muriatic acid, and by putting in a
piece of iron or zinc, the copper will fall down. Or, add to this
solution pure potash; dry and weigh the powder thrown down; every 5
parts of it contains 4 parts of copper.

Gray copper and red copper ores may be assayed by heating with charcoal,
(both powdered,) in a furnace. Malachite and azurite should be smelted
with borax; Copper pyrites and silicate of copper with soda or powdered
marble.

A ton of copper ore which contains ten per cent. of metal, pays $25 at
the furnace. The ore of copper when roasted, turns black; and when
thrown into nitric acid makes a sky-blue solution. A clean knife-blade
put into this solution will be coated with copper.

ASSAY OF IRON ORE.--Take a known quantity of the ore in fine powder and
mix thoroughly with dry borax (or with one part of fluor spar, one of
charcoal and four of salt,) and expose it for an hour in a covered
crucible lined with charcoal to a white heat in a wind-furnace for an
hour. A button of iron will be found at the bottom, which determines the
percentage.

ASSAY OF ZINC ORE.--If the weighed ore is roasted with powdered
charcoal, white flowers of zinc will be formed on a piece of cold iron
held over it. After thorough roasting, the residue should be weighed;
the loss is the oxide of zinc, and every 100 parts of this contain 81 of
metal.

All the ores of zinc will dissolve in either nitric or hot sulphuric
acid.

ASSAY OF TIN ORE.--Tin-stone will yield up its metal if mixed with
charcoal, borax and soda, and heated on the hearth of a furnace or
before a blow-pipe.

The presence of tin may be tested by dissolving the metal thus roasted
out, in aqua regia and adding a decoction of Brazil-wood: if the metal
was tin, the liquid will be colored a beautiful crimson.

ASSAY OF LEAD ORE.--Both galena and cerussite are rich ores, and when
abundant pay well. They are easily reduced by heat, the former being
usually mixed with charcoal and iron filings. If a western backwoodsman
wants shot or bullets, he kindles a fire in a hollow tree or an old
stump, puts some galena on the charred wood, and melts it down. After
cooling, he finds the metal at the bottom. The smelting of a ton of lead
costs about $6. The average price per ton of galena is $30. When galena
is dissolved in warm nitric acid, a clean plate of zinc placed in it
will be coated with brilliant blades of lead; if the galena contains
silver, a plate of copper will be served in the same way. A solution of
chromate of potash poured into a solution of lead ore in nitric acid
will throw down a yellow powder.

TO TEST THE PURITY OF GRAPHITE.--Its value depends upon the amount of
its carbon. Pulverize and then dry at a heat of about 350 degrees,
twenty grains of it; then place it in a tube of hard glass four or five
inches long, half an inch wide and closed at one end. Add twenty times
as much well dried oxide of lead and well mix. Weigh the tube and
contents, and afterwards heat before a blow-pipe till the contents are
completely fused and no longer evolve gases. Ten minutes will suffice
for this. Allow the tube to cool and weigh it. The loss in weight is
carbonic acid. For every twenty-eight parts of loss there must have been
twelve of carbon.




CHAPTER VI.

MINERAL SPRINGS.

     WHAT ARE MINERAL SPRINGS--GENERAL LOCATION--GAS SPRINGS--IRON
     SPRINGS--SULPHUR SPRINGS--ALUM SPRINGS--EPSOM SPRINGS--SALT
     SPRINGS--WARM SPRINGS--ARTESIAN WELLS AND OIL WELLS, AND WHERE TO
     BORE FOR THEM.


Any spring which contains a large amount of foreign matter, as gas,
salts and earthy ingredients, is called _mineral water_. The special
prominence of any ingredient gives it its particular name. Many iron
springs contain salt, salt springs contain iron, and both may contain
gas; the name is derived from the most prominent ingredient.

Our country is rich in mineral springs; there is not a State without
one. But in general they are most numerous in hilly or mountainous
regions, especially where the rocks are much deranged in position, or
“faulted,” as the miners say. As for example, in Eastern New York and in
the valley between the Blue Ridge and the Alleghany from Harper’s Ferry
to the Natural Bridge. The Pacific States, also, are as remarkable for
the number and variety of their mineral springs as for their metallic
ores.

CARBONATED OR GAS SPRINGS.--Springs of this class have a peculiar
sparkling character and are continually sending up bubbles of gas. When
the quantity of gas is small, it may be detected by adding a little lime
water which will give it a milky appearance and deposit a white
sediment; or, dip in a piece of blue litmus paper (which can be had of
most druggists), and if there is any carbonic acid gas in the water, it
will be reddened; or, pour in a little vinegar, stir well, and then add
a little finely powdered sugar, when the gas, if it is there, will rise
in small bubbles.

The most celebrated carbonated springs are the following: Saratoga and
Ballston, N. Y.; Clarendon, Vt.; Sweet Springs in Shover’s Valley, Pa.;
Bladon and Bailey Springs, Ala.; “Boiling Springs” near Pike’s Peak,
Col.; Beer Springs near Bear River, Or. These springs contain salt,
soda, magnesia, lime and iron, and are sometimes classed as _saline_,
_soda_ or _chalybeate_ springs.

CHALYBEATE OR IRON SPRINGS.--The presence of iron in a spring may be
ascertained by pouring into it an infusion of nut-galls, of logwood or
of tan-bark, which will change it immediately to a black or dark color.
If the water contains much iron, it may be recognized by its inky taste
and by a yellowish powder on the border of the spring or at the bottom
of a tumbler when allowed to stand awhile.

If waters have a cool but earthy taste, they contain lime; if bitter,
they have magnesia. The “soda springs,” so called, are often only
saline, carbonated or magnesia waters.

The most famous iron springs are at Saratoga, Sandlake and Catskill, N.
Y.; West Bethel, Fryeburg, Eberne and Bethel, Me.; Schooley’s Mountain
in Washington, N. J.; Bedford, Pittsburg, Frankfort and York, Pa.;
Brandywine Springs, Del.; Red Sweet Springs in Monroe County, Rawley’s
Spring in Rockingham County, and Huguenot Springs in Powhattan County,
Va.; in Bath County, Ky.; Yellow Springs, O.; twenty miles east of
Knoxville, Tenn.; Madison County, Geo.; Raymond and Lynchburg, Miss.;
near Ogden City, Utah; near Mt. Shasta, Col.

SULPHUR SPRINGS.--These are easily recognized by their unpleasant odor,
resembling that of rotten eggs. The water blackens silver and a solution
of sugar of lead.

Sulphur springs are very numerous. The best known are at Saratoga,
Sharon, Clifton, Avon, Manlius, Chittenango, Dryden and Richfield, N.
Y.; Highgate and Newburg, Vt.; Togus, Bethel and West Newfield, Me.;
Shover’s Valley, Carlisle and Doubling Gap, Pa.; Winchester and
Warrenton, Va.; Greenbrier and Monroe Counties, W. Va.; Bath County,
Ky.; White’s Creek near Nashville and in Granger County, Tenn.;
Spartanburg, S. C.; Butts County, Geo.; Tallahatta, Ala.; Tampa, Fla.;
near Bitter Creek and Great Salt Lake, Utah; along the Yellowstone
River, Mont.; Jackson, Cal.

ACID OR ALUM SPRINGS.--These waters have a more or less sour taste and
redden blue litmus-paper.

They are found at Byron and Oak Orchard, N. Y.; Blossburg, Pa.; Bath,
Richmond and Rockbridge, Va.

MAGNESIAN OR EPSOM SPRINGS.--These have a bitter taste. To test any
water for magnesia, add to a glass of it a solution of phosphate of soda
and some hartshorn; if magnesia is present, the liquid first becomes
turbid, and finally minute crystals fall to the bottom.

There are Epsom springs at Harrodsburg and Perryville, Ky.; Westport,
O.; Raymond, Miss.; Orange County, Ind.; Scott County, W. Va.

SALINE OR SALT SPRINGS.--These contain a large percentage of common
salt, and are recognized by their taste. They generally contain many
ingredients, (generally seven or eight,) but the salt predominates. A
well should contain at least ten per cent. of salt to pay for working.
The Syracuse spring yields a bushel of salt to every thirty-three
gallons; while the Great Salt Lake contains 22 per cent. Among the most
important salt wells are those at Syracuse, Salina and Liverpool, N. Y.;
Lubec, Me.; Shannondale, Va.; Bath County, Ky.; Athens County, O.;
Hartford, Ind.; Saginaw, Mich.; Oneida, Idaho.

THERMAL OR WARM SPRINGS.--Any spring is so called, the temperature of
which throughout the year is above that of the soil around it. They
generally occur near the line of junction between the granite or igneous
rocks and the stratified rock (slate or limestone) resting upon its
flanks. The temperature of such waters in the United States ranges from
73 to 200 degrees, the latter being reached by the Geysers of Montana.
Many iron and sulphur springs are also thermal.

The most noted warm springs are at Lebanon, N. Y.; in Bath, Berkley,
Monroe and Scott Counties, Va.; Buncombe Counties, N. C.; French Brood
River, Tenn.; Meriwether County, Geo.; Washitaw, Ark.; Salt Lake Valley,
Utah; near Pyramid Lake, Nev.; along the Malheur and Fall Rivers, Or.;
Lincoln Valley, Idaho; on Gardiner’s River, in Madison County, and
especially in the Yellowstone Basin, Mont.

ARTESIAN WELLS.--To sink a flowing well with any reasonable prospect of
success, it is essential that the spot selected should be lower than
land in the vicinity, although those higher elevations may be several
miles away. The layers of the rocks, also, should dip _towards_ the spot
rather than away from it. The best indication, but not a certain one, is
a _great_ basin-shaped valley, to the centre of which the rocks dip on
one or more sides. Sandy, lime and slate rocks are more propitious than
granite.

OIL WELLS.--Where there are marks of disturbance and misplacement of the
rocks, there the experienced sink wells. Rugged hills and
sharply-defined valleys are, generally, signs of such dislocation. The
line or “break” from which the rocks dip like the roof of a house is
considered most favorable. There is no such thing as an “oil rock,” for
the oil is found at different depths, and the fissure containing it is
more or less vertical. In Pennsylvania, the greatest flowing wells have
been found in the third sand rock. No limestone has afforded any large
supply of oil. Coal in no large quantities is ever found upon or in the
immediate vicinity of the oil territory. The “show of oil” increases in
value as a sign, with the depth at which it is found. Especially is the
finding of a large amount of imprisoned gas, though no oil may be
present, regarded as a good indication that oil is near. In the
bituminous coal region, a gas spring indicates the probable existence of
oil in the rocks below. But generally, “surface shows” are seductive.
The great oil belt runs south-westerly from Oil Creek, Pa., to Burning
Springs, West Va. But Ohio, Kentucky, Tennessee, Georgia, Alabama,
Missouri, Texas, Illinois, Indiana, Michigan and Southern California are
also rich in petroleum.




CHAPTER VII.

ARTIFICIAL JEWELRY--HOW MADE AND HOW DETECTED.

     MOCK DIAMONDS--“PARIS BRILLIANTS”--THE MANUFACTURE OF PASTES--FALSE
     RUBY, TOPAZ, SAPPHIRE, EMERALD AND CARNELIAN--HOW TO DISTINGUISH
     TRUE AND FALSE GEMS--IMITATION PEARL AND CORAL--ARTIFICIAL
     GOLD--LIST OF PRECIOUS STONES.


“Bristol Stones,” “Irish Diamonds,” “Cape May Diamonds,” and “California
Diamonds,” are skillfully-cut quartz crystals. They are easily detected
by the file and by their lightness.

“Paris Brilliants” are more dangerous counterfeits, and are very often
sold for genuine. The great establishment of Boarguiguon, in Paris, is
the most famous manufactory of artificial gems in the world, employing
about one hundred hands. The gems are such perfect imitations that they
can be distinguished from real stones only by the closest scrutiny of
those experienced in such matters. They fail chiefly in hardness; in
brilliancy and gravity they nearly or quite equal the genuine.

Nature has made the most precious stones with the most common materials.
The diamond is purified charcoal; while the matter of clay and white
pebbles is the base of all other gems.

The chemist has imitated nature in the production of colored gems. The
base of these imitations, called “pastes,” is “_strass_”--a white glass
compound of 300 parts of pure sand, 96 of potash, 27 of borax, 514 of
white lead, and one of arsenic. The mixture is put into a crucible and
kept at a high heat for 24 hours. This is the philosopher’s stone which
competes with Golconda. The uncolored glass is used in making mock
diamonds and white topaz. Another paste which has very great brilliancy,
and, unfortunately, the same gravity as the diamond, is made by melting
100 parts of pure sand, 150 of red lead, 30 of calcined potash, 10 of
calcined borax and one of arsenic, keeping the mixture melted for two or
three days and then cooling very slowly. Each ingredient is separately
reduced to a fine powder.

FALSE RUBY is made by fusing together of strass one ounce and six drams,
glass of antimony 37 grains, and purple of cassius one grain; then add
eight parts more of strass and fuse for thirty hours; cool and remelt
pieces in a blow-pipe. Or, melt five ounces of strass and one dram of
manganese.

FALSE TOPAZ can be made from 1008 grains of strass, 43 grains of glass
of antimony and one grain of purple of cassius.

FALSE SAPPHIRE.--Add to eight ounces of strass 52 grains of pure oxide
of cobalt.

FALSE EMERALD.--To one pound of strass add one dram of verdigris and
fifteen grains of crocus martis. Or, take 2304 grains of strass, 21
grains of green oxide of copper, and one grain of oxide of chrome. Or,
take an ounce and a half of rock-crystal, six drams of dry soda, two
drams of dry borax, two drams of red lead, one dram of nitre, twenty
grains of red oxide of iron, and ten grains of green carbonate of
copper.

FALSE CARNELIAN.--Strass two pounds, glass of antimony one pound, rouge
two ounces, manganese one dram.

FALSE AMETHYSTS AND OPALS are manufactured; but the fine opal defies
imitation, and the amethyst is too common in nature to allow much margin
for the “pastes.”

In distinguishing true and false gems, no one character should be
depended upon. All genuine stones will bear rough handling; if the
merchant says “hands off,” refuse to purchase. Any gem worth buying is
worth testing.

First: try the _hardness_. The file will make no impression on the
diamond and ruby, and will with difficulty scratch the other gems; while
the “pastes” are easily marred. All the precious stones scratch window
glass, although opal will not attack common bottle glass. All imitations
easily yield to sand. The sapphire is the hardest of colored gems, and
opal is the softest. The emerald will hardly scratch rock-crystal; its
counterfeit not at all. Topaz will scratch ordinary ruby, but will not
touch sapphire.

Secondly: as to _weight_. This is the most accurate method, but the
stone must be taken from its setting. The mode of taking the gravity has
already been given (page 13), and the amount of each is stated in
Chapter II. Garnet is the heaviest of gems; weighed in water it loses
only one-fourth of its weight; _i. e._, if a red garnet be suspended by
a fine thread from a delicate balance and immersed in a glass of water
under it, one-quarter of its ordinary weight in air must be added to the
pan from which it is suspended to restore the equilibrium. In like
manner, ruby and sapphire lose a little more. The diamond and white
topaz lose two-sevenths of their weight. Rock-crystal, amethyst,
carnelian and agate lose five-thirteenths; and opal about one-half,
being the lightest of gems. The emerald loses more than one-third.

As “paste” _can_ be made so as to have the same specific gravity as the
genuine article, this test alone can not be relied upon; but very few of
the imitations are so carefully made. The test is very convenient in
distinguishing gems of like color from each other, as oriental ruby,
spinel ruby and red tourmaline, and green tourmaline and emerald.

Thirdly: characteristics depending on _light_ and _electricity_. It is
not easy to look through a diamond of the first water, while imitations
readily permit objects to be seen through them. A very delicate and
perfect test of a diamond, distinguishing it from all colorless gems, as
white topaz, white sapphire and white zircon, but not from “pastes,” is
to look through it at a pin-hole in a card. This requires some
dexterity, and the gem should be fixed to a steady object by a bit of
wax at a proper distance. A true diamond will show but one hole, all the
others will show two. As white topaz, when large, is a magnificent
stone, it is often palmed off for a diamond of great value; but this
test is invariably certain.

A true diamond retains its brilliancy under water.

When a colored stone is placed in the path of the solar spectrum (the
row of seven colors into which sunlight is separated by a prism), its
color will vary with the portion of the spectrum which falls upon it;
and two stones of the same color, but of a different nature, will
exhibit different effects. Thus, a paste placed beside a fine colored
gem, betrays its worthlessness. A simpler method of testing stones is to
look at them through a bit of glass, colored red, yellow, blue or green.
Every stone will exhibit, under this test, properties peculiar to
itself, and by which its

[Illustration: SEARCHING FOR DIAMONDS.]

nature may be recognized. This is also a severe test for the purity of
tint; for if pure and unmixed, the stone will appear completely black in
every other light but its own color. Milky and turbid stones can not
bear this test.

A first-class ruby has the color of the blood as it spirts from an
artery. The deeper the hue of the emerald the more it is valued; it
loses none of its brilliancy by artificial light. The pale rose topaz,
the kind most esteemed, is artificially colored by heating it.

If topaz or tourmaline be gently heated, it becomes electric and will
attract a thread or suspended pith-ball. No imitation will do this. All
real gems when rubbed will attract the pith-ball, and retain the power a
long time; the pastes also become electric, but soon lose their
attraction. Rub a glass tube with a piece of flannel and bring it near a
suspended pith-ball; the latter will be strongly attracted and then
repelled. Immediately rub a genuine diamond and bring it near the ball,
and it will be attracted. A paste diamond thus rubbed would repel it.

Finally: the breath remains much longer on the pastes than on real gems.
The former also betray under a magnifying glass small air bubbles.
Diamonds and other first-class stones are always cold to the touch.

FALSE PEARLS.--These are glass beads coated with a mixture of three
ounces of scales of the blay or bleak fish, half an ounce of fine glue,
one ounce of white wax and one ounce of pulverized alabaster. Powdered
opal is sometimes used; also the powdered pearl of the oyster and other
shells soaked in vinegar, and made up with gum tragacanth. Artificial
pearls are usually brittle, and do not weigh more than two-thirds as
much as the genuine.

FALSE CORALS.--These are made of resin and vermilion; or of marble
powder made into a paste with varnish or soluble glass and a little
isinglass, colored by Chinese vermilion, and then moulded. They are
used for setting in cheap jewelry. The knife shows it to be too soft to
be genuine.

ARTIFICIAL GOLD.--The following oroid or imitation gold is sometimes
sold for the genuine article which it closely resembles. Pure copper,
100 parts by weight, is melted in a crucible, and then 6 parts of
magnesia, 3.6 of sal-ammoniac, 1.8 of quicklime and 9. of tartar are
added separately and gradually in the form of powder. The whole is then
stirred for about half an hour, and 17 parts of zinc or tin in small
grains are thrown in and thoroughly mixed. The crucible is now covered
and the mixture kept melted for half an hour longer, when it is skimmed
and poured out.

Any imitation of gold may be detected by its weight, which is not
one-half of what it should be, and by its dissolving in nitric acid
while pure gold is untouched.




PRECIOUS STONES.

ARRANGED ACCORDING TO COLOR AND IN ORDER OF HARDNESS.


_Limpid._

Diamond,
Sapphire,
Topaz,
Rock-Crystal.


_Blue._

Sapphire,
Topaz,
Spinel,
Aquamarine,
Indicolite,
Turquoise,
Kyanite.


_Green._

Oriental Emerald,
Chrysoberyl,
Emerald,
Chrysoprase,
Chrysolite,
Amazon Stone,
Malachite.


_Yellow._

Diamond,
Topaz,
Fire-Opal.


_Red._

Sapphire-Ruby,
Spinel-Ruby,
Brazilian-Topaz,
Hyacinth,
Carnelian,
Rubellite,
Garnet.


_Violet._

Oriental Amethyst,
Amethyst.


_Black and Brown._

Diamond,
Tourmaline,
Hyacinth,
Garnet.




CHAPTER VIII.

DISCOVERY OF GOLD IN CALIFORNIA.[4]


It was on the 19th day of January, 1848, that James W. Marshall, while
engaged in digging a race for a saw-mill at Coloma, about thirty-five
miles eastward from Sutter’s Fort, found some pieces of yellow metal,
which he and the half-dozen men working with him at the mill supposed to
be gold. He felt confident that he had made a discovery of great
importance, but he knew nothing of either chemistry or gold-mining, so
he could not prove the nature of the metal nor tell how to obtain it in
paying quantities. Every morning he went down to the race to look for
the bits of the metal; but the other men at the mill thought Marshall
was very wild in his ideas, and they continued their labors in building
the mill, and in sowing wheat and planting vegetables. The swift current
of the mill-race washed away a considerable body of earthy matter,
leaving the coarse particles of gold behind; so Marshall’s collection of
specimens continued to accumulate, and his associates began to think
there might be something in his gold mines after all. About the middle
of February, a Mr. Bennet, one of the party employed at the mill, went
to San Francisco for the purpose of learning whether this metal was
precious, and there he was introduced to Isaac Humphrey, who had washed
for gold in Georgia. The experienced miner saw at a glance that he had
the true stuff before him, and, after a few inquiries, he was satisfied
that the diggings must be rich. He made immediate preparation to go to
the mill, and tried

[Illustration: THE SAW-MILL OF COLOMA.

THE PLACE WHERE GOLD WAS FIRST DISCOVERED IN CALIFORNIA.]

to persuade some of his friends to go with him; but they thought it
would be only a waste of time and money, so he went with Bennet for his
sole companion.

He arrived at Coloma on the 7th of March, and found the work at the mill
going on as if no gold existed in the neighborhood. The next day he took
a pan and spade, and washed some of the dirt in the bottom of the
mill-race in places where Marshall had found his specimens, and, in a
few hours, Humphrey declared that these mines were far richer than any
in Georgia. He now made a rocker and went to work washing gold
industriously, and every day yielded to him an ounce or two of metal.
The men at the mill made rockers for themselves, and all were soon busy
in search of the yellow metal. Everything else was abandoned; the rumor
of the discovery spread slowly. In the middle of March Pearson B.
Reading, the owner of a large ranch at the head of the Sacramento
valley, happened to visit Sutter’s Fort, and hearing of the mining at
Coloma, he went thither to see it. He said that if similarity of
formation could be taken as a proof, there must be gold-mines near his
ranch; so, after observing the method of washing, he posted off, and in
a few weeks he was at work on the bars of Clear Creek, nearly two
hundred miles north-westward from Coloma. A few days after Reading had
left, John Bidwell, now representative of the northern district of the
State in the lower House of Congress, came to Coloma, and the result of
his visit was that, in less than a month, he had a party of Indians from
his ranch washing gold on the bars of Feather River, twenty-five miles
north-westward from Coloma. Thus the mines were opened at far distant
points.

The first printed notice of the discovery of gold, was given in the
California newspaper published in San Francisco on the 15th of March. On
the 29th of May the same paper, announcing that its publication would be
suspended, says:--“The whole country, from San Francisco to Los
Angelos, and from the sea-shore to the base of the Sierra Nevada,
resound with the sordid cry of _gold! gold! gold!_ while the field is
left half planted, the house half built, and everything neglected but
the manufacture of picks and shovels, and the means of transportation to
the spot where one man obtained one hundred and twenty-eight dollars’
worth of the real stuff in one day’s washing; and the average for all
concerned, is twenty dollars per diem.”

The first to commence quartz mining in California were Capt. Wm. Jackson
and Mr. Eliason, both Virginians, and the first machine used was a
Chilian mill.

The Reid Mine, in North Carolina, was the first gold mine discovered and
worked in the United States, and the only one in North America from
which, up to 1825, gold was sent to the Mint.




CHAPTER IX.

     DISCOVERY OF SILVER IN NEVADA, AND UNITED STATES GOLD AND SILVER
     STATISTICS.


Separated from California by the snowy chain of the Sierra, the State of
Nevada has been celebrated, since 1860, for its silver mining. In
November, 1859, the news of the discovery of silver mines near Lake
Washoe was confirmed at San Francisco; and in June, 1860, the mines of
Washoe, the central western portion of the State, had already sent such
rich results to Europe, that the French Ministers of Finance and
Commerce despatched a mining engineer to Nevada to make a close
inspection of these wonderful mines. It seemed as if the world were
about to be inundated with silver, as it had been by gold ten years
previously; and what would those economists now say, who had only
recently counselled that the value of gold coin should be lowered or
that gold should be demonetized on account of the disturbed relation of
these precious metals--the bases of the standard of payment throughout
the world generally. Whilst the French engineer visited Nevada and
prepared his report, the miners of Washoe continued working their veins
of metal. At the present time, 1881, the mines on the eastern slope of
the Sierra Nevada annually produce about $12,500,000 of silver, chiefly
from the Comstock lode; the total yield of gold from the quartz mines of
California is about $17,000,000 per annum. The Comstock lode, in the
State of Nevada, may be ranked among the most productive metalliferous
deposits ever encountered in the history of mining enterprise; its
productive capacity, as now being developed, surpassing, if the mass of
its ores do not in richness equal, those of the most famous mines of
Mexico and Peru.

The known limits of this lode cover a space of 22,546 feet in a nearly
due north and south direction (magnetic). The variation of the needle in
that locality is 16½ degrees east. Upon this extensive seat of
metalliferous deposits, the mines are divided into three groups: the
Virginia Group, seventeen mines, with claims of 13,549⅓ feet; Gold
Hill Group, nine mines, of 6,397¼ feet; American Flat Group, three
mines, of 2,600 feet. The three groups of twenty-nine mines thus occupy
a total length on the lode of 22,546 feet. The Comstock lode was
discovered in 1859, by a pit sunk for a water hole on the ground of the
Ophir mine; milling the ore began in October of the same year, but the
amount of bullion taken out in 1860 is estimated at but $100,000. Since
then the Comstock has become the greatest gold and silver mine in the
world. To the end of 1878 the yield was estimated at $291,162,205, as
follows: From 1860 to 1870 inclusive, of gold and silver together,
unclassified, $102,466,240; 1871 to 1878 inclusive, gold, $88,691,498,
silver, $91,278,623; 1877 and 1878, gold and silver, unclassified,
$1,725,844. Making allowance for the loss by slimes and tailings, the
gross contents of the lode as worked up to 1878 are estimated at
$363,961,205. About 6,500,000 tons of ore have been extracted in this
time, which a good authority estimates of an average value to the
company of $45 per ton of 2,000 pounds.[5]


ANNUAL PRODUCTION of GOLD and SILVER in the UNITED STATES from 1853 to
1880, inclusive.

[From the Reports of the Director of the Mint.]

-------+-------------------------+------------
       |       PRODUCTION.       |
 YEAR. +------------+------------+   TOTAL.
       |   Gold.    |  Silver.   |
-------+------------+------------+------------
       | _Dollars._ | _Dollars._ | _Dollars._
 1853  | 65,000,000 |            | 65,000,000
 1854  | 60,000,000 |            | 60,000,000
 1855  | 55,000,000 |            | 55,000,000
 1856  | 55,000,000 |            | 55,000,000
 1857  | 55,000,000 |            | 55,000,000
 1858  | 50,000,000 |    500,000 | 50,500,000
 1859  | 50,000,000 |    100,000 | 50,100,000
 1860  | 46,000,000 |    150,000 | 46,150,000
 1861  | 43,000,000 |  2,000,000 | 45,000,000
 1862  | 39,200,000 |  4,500,000 | 43,700,000
 1863  | 40,000,000 |  8,500,000 | 48,500,000
 1864  | 46,100,000 | 11,000,000 | 57,100,000
 1865  | 53,225,000 | 11,250,000 | 64,475,000
 1866  | 53,500,000 | 10,000,000 | 63,500,000
 1867  | 51,725,000 | 13,500,000 | 65,225,000
 1868  | 48,000,000 | 12,000,000 | 60,000,000
 1869  | 49,500,000 | 12,000,000 | 61,500,000
 1870  | 50,000,000 | 16,000,000 | 66,000,000
 1871  | 43,500,000 | 23,000,000 | 66,500,000
 1872  | 36,000,000 | 28,750,000 | 64,750,000
 1873  | 36,000,000 | 35,750,000 | 71,750,000
 1874  | 40,000,000 | 32,000,000 | 72,000,000
 1875  | 40,000,000 | 32,000,000 | 72,000,000
 1876  | 46,750,000 | 38,500,000 | 85,250,000
 1877  | 45,100,000 | 38,950,000 | 84,050,000
 1878  | 50,000,000 | 49,000,000 | 99,000,000
 1879  | 38,900,000 | 40,812,000 | 79,712,000
 1880  | 36,000,000 | 37,700,000 | 73,700,000
-------+------------+------------+------------

The consumption of Gold and Silver in the Arts and Manufactures from
1874 to 1879, inclusive, in the United States, was estimated by the
Director of the Mint, in 1879, as follows:

-------+------------+------------
 YEAR. |   Gold.    |  Silver.
-------+------------+------------
 1874  | $4,578,328 | $4,406,560
 1875  |  5,382,098 |  4,237,841
 1876  |  4,153,184 |  3,812,018
 1877  |  3,687,192 |  3,774,240
 1878  |  5,078,701 |  5,210,152
 1879  |  3,899,125 |  5,977,300
-------+------------+------------




INDEX.


            PAGE

Acid or alum springs, 109

Agate, 20, 21
  localities, 21
  value, 20

Alleghenies, 14

Alum, 21
  localities, 21, 22
  springs, 109
  value, 21

American Flat group, silver mines, 136

Amethyst, 22
  false, how made, 117
  localities, 22
  value, 22

Anthracite, 22, 23
  localities, 23
  value, 23

Antimony ore, 23, 24
  localities, 23
  value, 23

Artesian Wells, 111, 112

Artificial gold, how made, 125
  jewelry, how made and detected, 114-125

Asbestus, 24
  localities, 24
  value, 24

Asphaltum, 24, 25
  localities, 25
  value, 25

Assay of copper ore, 100-102
  gold ore, 95-98
  iron ore, 102
  lead ore, 103, 104
  ores, 92-104
  silver ore, 99, 100
  tin ore, 102, 103
  zinc ore, 102

Atlantic coast, 14

Azurite, 25
  localities, 25
  smelting, 101
  value, 25


Baryta, localities, 26
  or heavy spar, 26
  value, 26

Bidwell, John, 130-132

Bituminous coal, 27
  localities, 27
  region, 14

Blende, 27, 28
  localities, 28
  value, 28

Blowpipe, 17

Bog iron ore, 29
  localities, 29
  value, 29

Boring, 83

Brazil, diamonds in, 84

Bristol stones, 114

Brittle silver ore, 30
  localities, 30
  value, 30

Brown coal, 30
  localities, 30
  value, 30

Brown Hematite or Limonite, 56, 57


Calamine, 31
  localities, 31
  value, 31

California diamonds, 114
  discovery of gold in, 127-133

Cannel coal, 31, 32
  localities, 32
  value, 32

Cape May diamonds, 114

Carbonated or gas spring, 106, 107

Carnelian, 32
  false, how made, 117
  localities, 32
  value, 32

Celestine, 32, 33
  localities, 33
  value, 33

Cerussite, 33
  and Galena, reduction of, 103
  localities, 33
  value, 33

Chalybeate or iron springs, 107, 108

Chromic iron, 34
  localities, 34
  value, 34

Cinabar, 34, 35
  localities, 35
  value, 35

Clear Creek, Cal., gold in, 132

Coal, anthracite, 22
  bituminous, 27
  brown, 30
  cannel, 31, 32

Cobalt pyrites, 35
  localities, 33
  value, 35

Coloma, Cal., discovery of gold there, 127

Colorado silver lodes, 89

Colors, distinction of minerals by, 12

Comstock Lode, 135-137
  gold and silver produced from, 136, 137

Connecticut river valley, 14

Copper, 36
  glauce, 36
    localities, 36
    value, 36
  gray copper ore, assaying, 101
    localities, 36
  nickel, 37
    localities, 37
    value, 37
  ore, assay of, 100-102
    gray, 51
    red, 65
    red, assaying, 101
    variegated, 78
  ores, test for silver, 99
    testing, 100-102
    silver in, 101
  percentage of in ores, which will pay, 101
  pyrites, 37, 38, 90
    localities, 38
    smelting, 101
    value, 38
  searching for, 90
  seldom in new formations, 90
  silicate of, 70
    smelting, 101
  value, 36
  where found, 14, 90

Corals, false, how made, 124


Descriptive list of useful minerals, 20-80

Diamond, 41
  estimation of the value of, 86
  imperfections of, 86
  localities, 41
  value, 41

Diamonds, characteristics of, 85, 86
  colors of, 83
  finest, 84
  in Brazil, 84
  in their native state, 83
  mode of discovering in Brazil, 84
  prospecting for, 83-87
  where found, 87

Directions for determining specimens by the key, 15-19

Discovery of silver in Nevada, 134-137


Effervescence in minerals, 12

Eliason, Mr., 133

Emerald, false, how made, 116
  to test, 118

Emery, 41, 42
  localities, 42
  value, 42

Epsom springs, 109, 110


False amethyst, how made, 117
  carnelian, how made, 117
  corals, how made, 124

False emerald, how made, 116
  opal, how made, 117
  pearls, how made, 124
  ruby, how made, 116
  sapphire, how made, 116
  topaz, how made, 116

Feather river, Cal., gold in, 132

Fluor spar, 42
  localities, 42
  value, 42

Franklinite, 43
  localities, 43
  value, 43


Galena, 43, 44
  and Cerussite, reduction of, 103
  localities, 44
  purest specimens poorest in silver, 91
  value, 43

Garnet, 44, 45
  localities, 45
  the heaviest of gems, 118
  to test, 118
  value, 45

Gas springs, 106, 107

Gems, to test by weighing in water, 118
  true and false, how to distinguish, 117-124

Glass, minerals which will not scratch, 16, 19
  minerals which will scratch, 15, 18

Gold, 46-50
  and platinum, washing for, 94, 95
  and silver consumed in the arts in the United States, 137, 138
  and silver, production of the United States, 137, 138
  and silver where they abound, 14
  artificial, how made, 125
  bearing rock, 88
  bearing sands, 88
  extraction of, 93
  Hill group, silver mines, 136
  how distinguished, 89
  imitation, how to detect, 125
  in California, discovery of, 127-133
  in California, first announcement of discovery, 132
  in quartz rock, to find the amount of, 98
  localities, 46-50
  mine first worked in the United States, 133
  ore, assay of, 95-98
  searching for, 87-89
  substances mistaken for, 89
  testing any substance supposed to contain, 97
  to separate from silver, 97
  to test the purity of, 98
  where found, 87-89

Granite regions, 14

Graphite, 50, 51
  localities, 50, 51
  to test the purity of, 104
  value, 50

Gravity, mode of determination of, 12

Gray copper ore, 51
  localities, 51
  value, 51

Gypsum, 14, 52
  localities, 52
  value, 52


Heavy spar or baryta, 26

Hematite, brown, 56, 57

Horizontal beds, 82

Horn silver, 53
  localities, 53
  value, 53

Humphrey, Isaac, 128


Indications for minerals, 81

Irish Diamond, 114

Iron, chromic, 34
  how it occurs, 94
  ore, 14
    assay of, 102
    bog, 29
    brown hematite, 56, 57
    lenticular, 56
    magnetic, 57,  58
    magnetic, found by the compass, 91
    micaceous, 62
    red hematite, 65, 66
    specular, 73, 74
  pyrites, 53, 54
    localities, 54
    value, 53, 54
  searching for, 91
  spathic, 73
  springs, 107, 108
  testing minerals for, 91


Jackson, Captain Wm., 133

Jasper, 54
  localities, 55
  value, 55

Jewelry, artificial, how made and detected, 114-125


Kaolin, 55, 56
  localities, 55
  value, 55


Lead ore, assay of, 103, 104
  to detect silver in, 99
  searching for, 90
  veins, thickest, 91
  where found, 90

Lenticular iron ore, 56
  localities, 56
  value, 56

Limestone regions, 14

Limonite or brown hematite, 56, 57
  localities, 57
  value, 57


Magnesian springs, 109, 110

Magnetic, 12
  iron ore, 57, 58
    found by the compass, 91
    localities, 58
    value, 58
  pyrites, 58, 59
    localities, 59
    value, 59

Malachite, 59, 60, 101
  localities, 59, 60
  value, 59

Manganese, oxyd of, 63, 64
  spar, 60
    localities, 60
    value, 60

Marble, 60, 61
  localities, 61
  regions, 14

Marshall, Jas. W., discovery of gold in California by, 127-131

Metals, found near their source, 82
  how they occur, 94

Mica, 61, 62
  localities, 62
  value, 62

Micaceous iron ore, 62
  localities, 62
  value, 62

Mineral riches, how discovered, 81
  springs, 105-112
    location of, 105
    no indications of ores, 83
    what are they, 105

Minerals as a source of our nation’s wealth, 9
  descriptive list of, 20-80
  regions which offer best inducements to search for, 14
  sections of the United States, richest in, 14
  species in the United States, how many, 11
  specific gravity of, 12, 13
  useful in the United States, 11
  which will not scratch glass, 16, 19
  which will scratch glass 15, 18

Mississippi Valley, 14

Money in the rocks, 9


Nickel, copper, 37

Nitre,  63
  localities, 63
  value, 63

Nodules, 82


Ochres, 91

Oil wells, 112, 113

Opal, false, how made, 117
  the softest of colored gems, 118

Opaque minerals, 12

Ore on a hillside, indications of, 82
  veins generally vertical, 82
  when it will pay, 92

Ores, assay of, 92-104
  minimum percentages of metal in which will pay, 93

Oxyd of Manganese, 63, 64


Pacific coast, 14

Panning, 94, 95

Paris brilliants, 114

Pastes, composition of, 115

Pearls, false, how made, 124

Platinum, 64
  localities, 64
  value, 64
  washing for, 94, 95

Pockets, 82

Precious stones, color and order of hardness, 126

Prospecting for diamonds, 83-87

Pyrites, iron, 53, 54
  cobalt, 35
  copper, 37, 38, 90
  magnetic, 58, 59
  testing for gold, 96
  yield of gold by, 97


Quartz mining in California, commencement of, 133
  ores, yield of, 96
  rock, to find the amount of gold in, 98
  testing for gold, 95, 96

Quicksilver, use of in assaying, 96


Reading, Pearson B., 131

Read mine, first gold mine worked in United States, 133

Red copper ore, 65
    localities, 65
    value, 65
  hematite, 65, 66
    localities, 66
    value, 65
  silver ore, 66
    localities, 66
    value,  66

Rennselaerite, 67
  localities, 67
  value, 67

River sand, worth working for gold, 98

Rock crystal, 67
    localities, 67
    value, 67
  salt, 68
    localities, 68
  suspected of containing silver, treatment of, 89

Rocky mountains, 14

Ruby, characteristics of, 85
  false, how made, 116
  spinel, 74
  to test, 118, 123

Russia, gold how obtained in, 94

Rutile, 68
  localities, 68
  value, 68


Saline or salt springs, 109, 110

Salt springs, 110

Sapphire, false, how made, 116
  the hardest of colored gems, 118
  to test, 118

Searching for copper, 90
  diamonds, 83-87
  gold, 87-89
  iron, 91
  lead, 90
  silver, 89, 90

Serpentine, 69
  localities, 69
  value, 69

Shaft, cost of sinking, 83

Silicate of copper, 70
  localities, 70
  smelting, 101
  value, 70

Silver, 70, 71
  and gold, consumption in the arts in the United States, 137, 138
  and gold, production of the United States, 137, 138
  glance, 71
    localities, 71
    reducing, 100
    value, 71
  horn, 53
  in copper ores, 101
  in lead and copper ores, 99
  in lead ore, to detect, 99
    to estimate the proportion of, 99, 100
  in Nevada, 134-137
  localities, 70
  native gold in, 97
  ore, assay of, 99, 100
    brittle, 30
    red, 66
  ores, rich reduction of, 100
  pure easily recognized, 99
  searching for, 80, 90
  to test a globule of for gold, 97
  to test copper ores for, 99
  where found, 89

Slate regions, 14

Smaltine, 72
  localities, 72
  value, 72

Smithsonite, 72
  localities, 72
  value, 72

Spar manganese, 60

Spathic iron, 73
  localities, 73
  value, 73

Specific gravity, mode of determination of, 12, 13

Specular iron ore, 73, 74
  localities, 74
  value, 74

Spinel ruby, 74
  localities, 74
  value, 74

Steatite, 75
  localities, 75
  value, 75

Stones, precious, color and order of hardness, 126

Strass for making false jewels, 115

Strontianite, 75, 76
  localities, 76
  value, 76

Sulphur, 76
  localities, 76
  springs, 108, 109


Testing minerals, 15-19

Thermal springs, 110, 111

Tin ore, 76, 77
    assay of, 102, 103
    localities, 77
    value, 76
  presence of, testing for, 103

Topaz, 77
  characteristics of, 85
  false, how made, 116
  localities,  77
  to test, 118, 120, 123
  value, 77

Tourmaline, 77
  localities, 77
  to test, 123
  value, 77

Translucent minerals, 12

Trap regions, 14

True and false gems, how to distinguish, 117-124


United States, consumption of gold and silver in the arts, 137, 138
  gold and silver statistics of, 137, 138

Useful minerals, descriptive list of, 20-80
 in the United States  11


Valuable minerals disguised, 10

Variegated copper ore, 78
  localities, 78
  value, 78

Veins, lodes and beds most valuable, 82

Virginia group, silver mines, 136


Wad, 78, 79
  localities, 79
  value, 78

Warm springs, 110, 111

Washing for gold and platinum, 94, 95

Washoe lake, silver mines near, 134

Wells, artesian, 111, 112

Willemite, 79
  localities, 79
  value, 79


Zincite, 79, 80
  localities, 80
  value, 79

Zinc ore, assay of, 102


FOOTNOTES:

 [1] The useful rocks, as granite, slate, sandstone, water-lime, etc.,
 are not included. By “granite region” is meant one having rocks like
 New England, and therefore unlike Western New York or Illinois.

 [2] That is, they are not so easily cut with a knife; they do not
 necessarily scratch marble.

 [3] Only the best known localities in the United States are given.
 For these we are indebted mainly to Professor Dana’s great work on
 Mineralogy.

 [4] From Simonin’s “_Underground Life_,” page 346.

 [5] Church. The Comstock Lode, its Formation and History, N. Y., 1879,
 pp. 1-5.