100 DESCRIPTIONS OF MINERALS. 
Claudetite is the same compound in trimetric crystallizations, from 
Portugal. 
General Remarks.—Arsenic is obtained for commerce chiefly from 
arsenopyrite (or mispickel), an iron sulph-arsenide, and from the nickel 
and cobalt arsenides, by first roasting off the sulphur, and then con- 
densing the arsenic, in the state of As, O, (‘‘ arsenous acid”) in large 
chambers. To obtain the material pure it is usually sublimed again 
in iron pots, in the upper part of which (artificially kept cool) it is 
condensed, mostly in a half-fused vitreous condition. To reduce the 
oxide to the metallic state it is heated with charcoal. In Devon and 
Cornwall the arsenicai ores occur with the tin ore, and a large amount 
of white arsenic is made. The metal arsenic forms a small part of 
some alloys ; the most important is that with lead for shot making. 
Native Antimony. 
Rhombohedral; RA h=87° 35’. Usually massive, with a 
very distinct lamellar structure ; sometimes granular. Color 
and streak tin-white. Brittle. H.=3-3°:5. G.=6°6-6°75. 
Composition. Pure antimony, often with a little silver, 
iron, or arsenic. B.B. on charcoal fuses easily and passes 
off in white fumes. 
Obs. Occurs in veins of silver and other ores in Dauphiny, 
Pohemia, Sweden, the Hartz, and Mexico. 
Stibnite.--Gray Antimony. Antimony Sulphide. 
Trimetric. In right rhombic prisms, with striated lateral 
faces ; J \J=90° 45’. Cleavage in the direction of the shorter 
diagonal, highly perfect. Commonly diver- 
gent columnar or fibrous. Sometimes massive 
granular. 
Color and streak lead-gray ; liable to tarn- 
ish. Lustre shining. Brittle; but thin lami- 
ne a little flexible. Somewhat sectile. H.=2. 
G. =4°5-4°62. 
Composition. Sb, 8,=Sulphur 28°2, anti- 
mony 71°8. Fuses readily in the flame of a 
candle. B.B. on charcoal it is absorbed, giv- 
ing off white fumes and a sulphur odor. 
Diff. Distinguished by its extreme fusibility 
and its vaporizing before the blowpipe. 
Obs. Stibnite occurs in veins with ores of silver, lead, 
zine, or iron, and is often associated with barite, spathic 
iron, or quartz. It occurs at Felssbanya and Schemnitz in 
Hungary ; at Wolfsberg in the Hartz; at Briunsdorf near 
Freiberg ; in Auvergne, Cornwall, Spain, and Borneo. 

