The San Juan Mines

tis with effervescence; in muriatic acid, without.

External Characters.-Color, brown, yellowish, or blackish brown; on the

Distinctive Characters.—Its chemical outside resembling black glazed earthcharacters. enware. Occurs stalactical, tuberous,

Composition.-Copper, from 88.5 to nodular, and amosphous. Structure, 91, oxygen, from 11.5 to 9.

BLUE CARBONATE OF COPPER

fibrous. Lustre, silky and resinous; yields to the knife. In a variety of this ore the structure is compact; lus

is found in primary and secondary tre, none; streak, yellowish brown; mountains.

External Characters. - Color, blue. Occurs massive, stalactical, incrusting, disseminated, and crystallized. Fracturc, imperfectly foliated, usually presenting broad fibres.

Chemical Characters. -Infusible with

out a flux; with borax gives a green glass. Dissolves in aquafortis with effervesence.

Distinctive Characters.-Insoluble in water; does not become magnetic under the blowpipe.

Composition.-Oxyd of Copper, 70;

carbonic acid. 24; water, 6.

Tests for Copper. To a solution of this metal present a plate of iron-re

fracture, conchoidal or earthy.

RED HEMATITE.

Chiefly in the primary, often in lead mines. It yields the best of iron for drawing and rolling.

External Characters.-Colors, bloodred and dark steel-gray. Occurs massive, and in plates; also, reniform, globular, and pulverulent. Fracture, uneven and earthy. Yields easily to the knife. Adheres to the tongue.

Specific gravity, 4.75.

Chemical Characters.-Infusible, but becomes magnetic.

Composition. Oxyd of iron, 90; sil

sult, metallic copper; potash-result, ver, 2; lime, 1; water, 3.

green precipitate; ammonia (hartshorn,)—result, blue color.

Copper smelts at 1996°; it is ductile, malleable, and tenacious; it is hard, elastic, and sonorous.

IRON.

SPECULAR OXYD OF IRON (IRON
GLANCE.)

Occurs chiefly in primary mountains, associated with magnetic iron, red hematite, quartz, etc.; also in secondary rocks. Affords good mallea

Is found in primary and second-ble iron. ary rocks. The ores from which the iron of commerce is extracted are:

BROWN HEMATITE.

Occurs abundantly in primary districts, and sometimes in secondary. It yields the finest kind of iron.

External Characters.-Color, steelgray, with a highly polished surface; often tarnished. Streak, cherry-red. Occurs crystallized in pyramidal dodecahedrons, hexahedral tables; also massive, disseminated, in concretions. Structure, lamellar. Lustre, brilliant,

The Kansas Pacific Railway has no rival in speed and equipments.

slightly attracted by the magnet. ing-the black variety affording the Specific gravity, 5.52.

Chemical Characters.-Infusible; insoluble in acids.

Distinctive Characters.-Yields a red powder when heated, and becomes magnetic.

Composition.-Iron, 69; oxygen, 31.

MAGNETIC OXYD OF IRON-(IRON SAND.)

Occurs imbedded in trap rocks, and called mountain ore. Furnishes best bar iron, and yields fifty to ninety per cent of the metal.

External Characters. — Color, ironblack. Occurs in minute grains; also in octahedral crystals. Fracture, conchoidal. Strongly magnetic. Powder, black,

Chemical Character. - Infusible by blowpipe.

Composition.-Oxyd of iron, 85.50 oxyd of titanium, 14; oxyd of manganese, 0.50.

SPATHIC IRON-(CLAY IRON ORE.)

best.

External Characters. Colors, yellow, white, brown, and black. Occurs massive, disseminated, with pyramidal impressions; also in granular distinct concretions-nodula, and crystallized. Structure, foliated or lameller. Lustre, shining vitreous. Streak, | white or yellowish brown. Yields to the knife; easily broken. Crystals usually small, and found in groups. Specific gravity, about 4.

Chemical Characters.-Are infusible, blackens, and becomes magnetic. Effervesces with muriatic acid. Heated with borax, it makes an olive-green glass.

Distinctive Characters. From the earthy minerals it is distinguished by its weight. From other iron ores, by crystalline, foliated cleavage; and blende, by its yielding magnetic iron.

Composition.-Oxyd of iron, 58; carbonic acid, 35; oxyd of manganese, 4.25; magnesia, 0.75; lime, 0.5.

Tests for Iron.-Infusion of galls, when added to iron dissolved in an acid, gives a black precipitate, (black ink;) prussiate of potash gives a blue precipitate, (blue ink.)

LEAD.

The ore which is generally wrought, and from which nearly all the lead of commerce is procured, is the

It occurs in veins in granite, gneiss, mica slate, clay-slate, and gray wacke, and in these it is associated with ores of lead, cobalt, silver; but seldom with nickel and bismuth; more frequently with galena, copper ore, iron pyrites, and antimony ore. In other veins it is accompanied with brown, red, and black iron ore, calcareous spear, and quartz. But the most extensive formations of this ore is in carboniferous limestone, in which it is arranged in thick beds. It is also found filling. It occurs in veins, beds, and imbedup amygdaloidal cavities in trap rocks, ded masses, in primary and secondary It is excellently adapted for steel-mak- mountains, but most frequently in the The Finest Scenery on the continent is seen by a trip over the Kansas Pacific

Railway.

SULPHURET OF LEAD

(GALENA.)

latter, and particularly in limestone. Lustre, shining and adamantine. Yields to the knife. Brittle. Structure, foliated. Specific gravity, 3, 7, to 4.

It is commonly associated with the ores of zinc, copper and iron, and often with those of silver. When it is found in the primary rocks, it is generally in granite. It is also found in alluvial deposits.

External Characters.-Colors, bluishgray, lead-gray, and on the outside, blackish-gray. Occurs amorphous, reticulated, and crystallized in cubes. and octahedrons. Structure, lamellated. Lustre, metallic. Perfectly sectile; soft. Very brittle. Opaque.

Chemical Characters.-When heated, first decrepitates, then emits the smell. of sulphur, melting into a globule of lead.

Distinctive Characters.-Blende, molybdena, and graphite are infusible. Composition.-Lead, sulphur, lime,

and silver.

Tests for Lead.-Glauber's salts, and an infusion of galls, give to a solution of this metal a white precipitate.

ZINC

is found in primary and secondary rocks.

Blende. (Mock Lead, False Galena, Black Jack.)

Occurs in veins in primary and secondary rocks, generally associated with galena, with iron and copper. This ore is commonly too widely disseminated in its gangue to make it profitable. It is, however, used after roasting in the preparation of brass.

Chemical Characters.-When heated, decrepitates. When thrown into the oil of vitroil, it gives the smell of rotten eggs.

Distinctive Characters. Infusible. Does not tinge borax green. Composition. Zinc, sulphur, iron, and silex.

CALAMINE.

Occurs in beds, nests, filling up or lining hollows, in secondary limestone and conglomerate rock; also in veins, usually along with oxyd of iron, and sometimes with galena.

External Characters.-Colors, gray, greenish, or brown-yellowish, and sometimes nearly white. Occurs crystallized, compact, amorphous, pseudomorphous, and cupriferous. Yields to the knife. Specific gravity, 3, 35 to 4, 41.

Chemical Characters.-Infusible; dissolves with effervescence in muriatic acid or warm aquafortis. Composition.-Oxyd of zinc and carbonic acid.

RED ORE OF ZINC.

Found in Iron mines; also in limestone.

External Characters. Color, red. Occurs massive and disseminated. Lustre, shining, by exposure becomes. dull. Structure, foliated. Yields to the knife. Brittle. Specific gravity,

External Characters. Colors, yellow, brown, and black. Occurs mas- 6, 22. sive, lamelliform, disseminated, in glanular concretions, and crystallized. uble with effervescence in acids.

Chemical Characters.-Infusible; sol

El Moro, two hundred and twenty miles from Silverton, reached via Kansas Pacific Railway.

Distinctive Characters.-Infusibility metallic. Softer than copper. Tarnishes. Melts at 476°. Specific grav

and weight.

The altitudes of different portions

COLORADO.

of the country is an interesting study, Mount Lizard, San Juan.........
as it has much to do with climate,
health, vegetation, physiological char-
acter and habits of the people, and in-
dicates, more or less, the location of
the precious metals.