102 DESCRIPTIONS OF MINERALS. 
Bismuthinite. A bismuth sulphide, Biz S;, in acicular crystals of a 
lead-gray color. ‘ 
Guanajuatite. A bismuth selenide, from Guanajuato, Mexico, called 
also frenzelite. Silaonive 1s a selenide from the same locality, of a 
lead-gray color. 
Bismite. Bismuth ochre, an impure oxide, grayish, te greenish and 
yellowish white, and massive or earthy, found with native bismuth. 
Tetradymite.—Bismuth Telluride. 
Hexagonal; R A R=81° 2’. Crystals often tubular, with 
a very perfect basal cleavage. Also massive, and foliated 
or granular. Lamine flexible, and soil paper. Lustre 
splendent metallic. Color pale steel-gray, a little sectile. 
H.=15—2. G.=7:2—7°9. 
Composition. Consists of bismuth and tellurium, with some- 
times sulphur and selenium, affording for the most part the 
formula Bi, (Te, 8),. A variety from Dahlonega, Georgia, 
gave Tellurium 48:1, bismuth 51:9=Bi, Te,; G.=7-642; 
Joseite is a bismuth telluride from Brazil, in which half the 
bismuth is replaced by sulphur; and Wehrlite is another 
ee sulphur, from Deutsch Pilsen, Hungary, having 
— 8°44, 
Obs. Found with gold in Virginia, North Carolina, and 
Georgia ; Highland, Montana Territory ; Red Cloud Mine, 
Colorado ; Montgomery Mine, Arizona. 
General Remarks. —The metal bismuth is obtained mostly from 
native bismuth. Besides the above ores, there are also others in which 
the metal is combined with silver, lead, and cobalt (pp. 116, 166) ; 
and a carbonate of bismuth, which occurs rarely in connection with 
ae poe or the ores of the metal, as a result of oxidation ; also 
a SULICHHE. 
IV. CARBON GROUP. 
The Carbon group in chemistry comprises carbon and 
silicon, in which the formula for the most prominent oxide 
is RO, Only carbon occurs native. 
Carbon occurs crystallized in the diamond and graphite ; 
as oxides, in carbon oxide, and carbon dioxide (ordinarily 
called carbonic acid); combined with hydrogen, or hydrogen 
and oxygen, in bitumen, mineral oils, amber, and a num- 
ber of native mineral resins, and mineral wax; and as the 
chief constituent of mineral coal, in which 1t is combined 
