Bismuthinite

minerals

aikinite

bismuth

stannite

Images
Formula: Bi2S3
Sulphide, forms series with aikinite and with stibnite
Specific gravity: 6.8 to 7.2
Hardness: 2
Streak: Grey
Colour: Lead grey to yellowish white
Solubility: Insoluble in hydrochloric acid and sulphuric acid; readily soluble in nitric acid
Common impurities: Pb,Cu,Fe,As,Sb,Se,Te
Environments:

Plutonic igneous
Pegmatites
Hydrothermal environments
Volcanic exhalation deposits

Bismuthinite occurs as an unaltered primary mineral in high temperature hydrothermal veins in tin and silver-cobalt deposits, in tourmaline-bearing copper deposits in granite, in some gold veins formed at high temperatures, and in recent volcanic exhalation deposits (Webmin, HOM), and also in pegmatites (Dana). Associated minerals include aikinite, arsenopyrite, bismuth, cassiterite, chalcopyrite, galena, pyrite, quartz, stannite, tourmaline and wolframite (Mindat, HOM).

Localities

At Kingsgate, Gough county, New South Wales, Australia, bismuthinite is relatively common in the wolframite pipe as masses of parallel fibres, and also as needles lining quartz vugs. It is commonly coated with bismutite when oxidised, a number of specimens contain minor bismuth, it is sometimes intergrown with cosalite or galenobismutite, and it also invades cleavage planes of molybdenite (AJM 14.1.20).

At the Cobar deposits, Robinson county, New South Wales, Australia, bismuthinite preferentially replaces gold, maldonite and native bismuth (AJM 11.2.66).

At the Almanda mine, Cherry Gardens, South Mount Lofty Ranges, South Australia, bismuth inclusions in chalcopyrite show some replacement by microcrystalline bismuthinite. Bismuthinite was also found replacing chalcopyrite along contacts between chalcopyrite and arsenopyrite (AJM 18.1.55).

At Maldon, Mount Alexander Shire, Victoria, Australia, bismuthinite is widespread although in minor quantities. It has been found replacing jonassonite, and both minerals may replace bismuth. Bismuthinite is clearly associated with a late episode of chloritic alteration (AJM 15.35).

At Llallagua, Rafael Bustillo, Potosí, Bolivia, bismuthinite is one of the earliest formed minerals in the veins. Some of the largest crystals of bismuthinite in the world come from here, as lath-shaped crystals to 30 cm long in vugs filled with iron sulphides or cassiterite, fluorapatite and wolframite (Minrec 37.2.129).

At Bastnäs Mines, Riddarhyttan, Skinnskatteberg, Västmanland County, Sweden bismuthinite occurs quite abundantly as small spots in the cerium ore, generally associated with allanite (Minrec 35.3.194-195).

At Westernhope Old Mine, Stanhope, County Durham, England, UK, bismuthinite occurs very rarely, in needles up to 1 mm long, embedded in quartz associated with chalcopyrite (JRS 13.67).

At the Emmons pegmatite, Greenwood, Oxford county, Maine, USA, bismuthinite has been found in close association with native bismuth. The Emmons pegmatite is an example of a highly evolved boron-lithium-cesium-tantalum enriched pegmatite (R&M 94.6.505).

At the Stettin complex, Wausau Intrusive Complex, Marathon county, Wisconsin, USA, bismuthinite forms rare clusters of bladed crystals in small vugs, generally with fluorite (R&M 94.2.184-185).

Back to Minerals