mineral formations containing bismuth in quantities that make commercial exploitation feasible. Bismuth is found in ores both in the form of native minerals and as an impurity in some sulfides and thio salts of other minerals. In world practice, approximately 90 percent of all recoverable bismuth is extracted as a by-product during the processing of lead-zinc, copper, and tin ores and concentrates containing hundredths and tenths of a percent bismuth. Deposits of actual bismuth ores containing 1 percent bismuth and more are rare. The bismuth comprising such ores is native bismuth (contains 98.5-99 percent Bi), bismuthinite Bi2S3 (81.30 percent), tetradymite Bi2Te2S (56.3-59.3 percent), cosalite Pb2Bi2S5 (42 percent), bismite Bi2O3 (89.7 percent), and bismuthite Bi2CO3(OH)4 (88.5-91.5 percent).
All endogenous deposits of bismuth ores are postmagmatic and hydrothermal and are genetically associated with granite intrusive complexes.
The main types of endogenous deposits of bismuthic ores are greisen and quartz vein formations with tungsten, beryl, molybdenite, bismuthinite, and cosalite (Chinese People’s Republic, Peru; in the USSR—Kazakhstan, eastern Transbaikalia, and other locations); scarn (scheelite, copper, and complex deposits) with bismuthinite and various thio salts of bismuth (Clifton and Bisbee in Arizona, USA); pyrites with bismuth, mostly in scattered form (Cerro de Pasco, Peru); hydrothermal—gold and bismuth (Australia [Victoria deposit], Canada, and the USA [including Alaska]); arsenic and bismuth (San Gregorio in Peru); copper and bismuth (Boccheggiano in the province of Tuscany, Italy); tin sulfides with bismuth minerals (the Bolivian tin belt—the Potosi, Oruro, La Paz, and Tazna deposits); polymetallic deposits containing bismuth (the USSR—eastern Transbaikalia, the Rudnyi Altai); and cobalt-nickel-silver-uranium-bismuth (Cobalt in Canada, Asuelo in Spain, and Annaberg and Schneeberg in the German Democratic Republic). Under exogenous conditions, the destruction of the primary deposits leads to the formation of alluvial and deluvial-alluvial deposits with basobismuthite and bismuthite.
REFERENCESBateman, A. M. Promyshlennye mineral’nye mestorozhdeniia. Moscow, 1949. (Translated from English.)
Trebovaniia promyshlennosti k kachestvu mineral’nogo syr’ia, part 28: B. I. Rozov, Vismut, 2nd ed. Moscow. 1961.
A. I. GINZBURG