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Formula: Bi2S3
Sulphide of bismuth,
stibnite group, forms series with
aikinite and with
stibnite
Crystal System: Orthorhombic
Specific gravity: 6.78 measured, 6.81 calculated
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).
Bismuthinite from Kingsgate - Image
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).
Bismuthinite from Llallagua - Image
At the Yaogangxian Mine, Yaogangxian W-Sn ore field, Yizhang County, Chenzhou, Hunan, China, bismuthinite occurs as
acicular silver-grey crystals with prismatic colourless quartz crystals
(AESS).
Bismuthinite from Yaogangxian - Image
At Johanngeorgenstadt, Erzgebirgskreis, Saxony, Germany, in the bismuth-rich
ore veins, bismuthinite occurred in small masses and in pockets with
quartz, skutterudite and
native bismuth. The acicular bismuthinite crystals are tin-white or
yellowish with some iridescence; they were known particularly from the Gottes Segen mine. Bismuthinite was
sometimes found in specimens of exceptional beauty, in small pockets in brown or reddish
chert. During the 1945–1958 period, bismuthinite was often met
with in the bismuth - cobalt -
nickel ore veins
(MinRec 55.5.590).
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).
Bismuthinite from the Bastnäs Mines - Image
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).
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