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Formula: Bi native element
Specific gravity: 9.7 - 9.8
Hardness: 2 to 2½
Streak: Lead grey
Colour: Silver white
Solubility: Slightly soluble in hydrochloric acid, readily soluble in sulphuric and nitric acid
Common impurities: Fe,Te,As,S,Sb
Environments:
Pegmatites
Metamorphic environments
Hydrothermal environments
Bismuth occurs in pegmatites and as an unaltered
primary mineral in
hypothermal (high temperature), tin ore veins. It is widespread, although not in large amounts, in
contact metamorphic formations, where it generally occurs in
chalcopyrite aggregates, and more rarely in
arsenopyrite (Ramdohr p379-380).
In pegmatites associated minerals include chalcopyrite,
pyrrhotite, arsenopyrite,
pyrite, bismuthinite,
molybdenite, sphalerite,
galena, wolframite and
cassiterite, as well as cubanite and
cobaltite.
In vein deposits associated minerals include skutterudite,
safflorite, löllingite,
bismuthinite, silver,
nickeline and breithauptite
(Ramdohr p379-380).
Localities
The Needle Hill Mine, Needle Hill, Sha Tin District, New Territories, Hong Kong, China, is a tungsten mine, abandoned
in 1967. The principal ore is wolframite, and the principal gangue mineral is
quartz. Molybdenum also occurs. The
mineralisation consists of a series of parallel fissure veins that cut through
granite. Wolframite and
quartz are the main minerals, but galena,
sphalerite, pyrite,
molybdenite and fluorite have also
been found here
(Geological Society of Hong Kong Newsletter 9.3.29-40).
The quartz-wolframite veins are of
high-temperature hydrothermal formation,
and grade into wolframite-bearing
pegmatites.
Wolframite is almost always associated with molybdenite. Other
associated minerals found occasionally include pyrite,
chalcopyrite, arsenopyrite,
sphalerite, bismuth,
fluorite, topaz and
cassiterite
(Hong Kong Minerals (1991). Peng, C J. Hong Kong Urban Council)
At the Emmons pegmatite, Greenwood, Oxford county, Maine, USA, bismuth has been found as 1-2 mm grains, often coated with
beyerite and associated with bismuthinite.
The Emmons pegmatite is an example of a highly evolved
boron-lithium-cesium-tantalum
enriched pegmatite
(R&M 94.6.505).
Bismuth-bearing minerals include:
Alloys
maldonite
Sulphides
bismuthinite
tetradymite
thalhammerite
Sulphide/Selenides
laitakarite
nevskite
Selenides
guanajuatite
kawazulite
paraguanajuatite
Tellurides
hedleyite
michenerite
tellurobismuthite
montbrayite
volynskite
Tellurobismuthides
moncheite
Bismuthides
froodite
insizwaite
kotulskite
polarite
sobolevskite
Sulphosalts
aikinite
benjaminite
cosalite
cupropavonite
emplectite
friedrichite
galenobismutite
gladite
gustavite
heyrovskýite
hodrušite
jonassonite
krupkaite
lillianite
lindströmite
matildite
miharaite
mozgovaite
nuffieldite
ourayite
pavonite
wittichenite
wittite
Oxides
bismite
bismutotantalite
oxybismutomicrolite
sillénite
sphaerobismoite
uranosphaerite
Halogenides
bismoclite
Carbonates
beyerite
bismutite
Tellurites
yecoraite
Phosphates
mrázekite
petitjeanite
Arsenates
asselbornite
atelestite
mixite
preisingerite
rooseveltite
tetrarooseveltite
walpurgite
Vanadates
dreyerite
namibite
pucherite
schumacherite
Molybdates
koechlinite
Nesosilicates
eulytine
Phyllosilicated
bismutoferrite
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