Bismuthinite(redirected from Bismuth trisulfide)
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(also called bismuth glance), a mineral belonging to the sulfide compounds. Chemical composition, Bi2S3 (81.30 percent Bi, 18.70 percent S), sometimes with admixtures of lead, copper, iron, arsenic, antimony, and other metals. It crystallizes in a rhombic system. The structure consists of linked Bi-S-Bi chains along the C axis. It normally forms acicular crystals, lamellae, radial growths, and fibrous or granular aggregates. It is opaque and silvery-white, with a metallic luster. It tarnishes and becomes covered with a gray film when exposed to air. Its hardness is 2-2.5 on the mineralogical scale, and its density is 6,780-6,810 kg per cu m.
Bismuthinite is formed in hydrothermal, greisen and contact-metasomatic deposits together with arsenopyrite; sulfides of Zn, Pb, Cu, and Fe; and minerals of tin, tungsten and molybdenum, native bismuth, and others. In a zone of oxidation it breaks down slightly and forms secondary oxides (bismite), sulfoxides, and aqueous bismuth carbonates. Bismuthinite is the main mineral from which bismuth is extracted.
G. P. BARSANOV