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Formula: Bi
Native element, arsenic group
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 Johanngeorgenstadt, Erzgebirgskreis, Saxony, Germany, native bismuth was among the most important products
of the mines. Bismuth generally occurred as fine disseminations in
quartz and chert-rich veins,
and as impregnations in the country rock. More rarely it was found as massive granular to leafy aggregates, and as
intergrowths with cobalt and nickel
ores. The feathery to herring-bone habit so well-known at Schneeberg was rare but formed specimens of exceptional
beauty; feathery crystal aggregates to 6 cm were found with pitchblende,
reddish brown chert or
dolomite. Bismuth specimens from the Gewerken Hoffnung mine are
particularly rich and fine. Small bismuth crystals, an extreme rarity, were found in the Gabe Gottes and
Gottes Segen mines
(MinRec 55.5.590).
Bismuth from Johanngeorgenstadt -
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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
driekopite
froodite
maldonite
polarite
Sulphides - the sulphide anion is S2-
bismuthinite
demicheleite-(Br)
demicheleite-(Cl)
ikunolite
joséite-A
laitakarite
nevskite
tetradymite
thalhammerite
vymazalováite
zipserite
Sulphosalts - sulphide minerals with the general formula AmBnXp, where A represents a metal , B
usually represents a semi-metal and X is sulphur or rarely selenium and/or tellurium
aikinite
aschamalmite
benjaminite
berryite
buckhornite
cosalite
cuprobismutite
cupromakovickyite
cupropavonite
eldragónite
emplectite
friedrichite
galenobismutite
gladite
gustavite
heyrovskýite
hodrušite
holubite
jonassonite
krupkaite
kupčíkite
lillianite
lindströmite
makovickyite
malyshevite
matildite
miharaite
mozgovaite
nuffieldite
ourayite
padĕraite
pavonite
pekoite
terrywallaceite
treasurite
vikingite
wittichenite
wittite
Selenides - the selenide anion is Se2-
guanajuatite
kawazulite
padmaite
paraguanajuatite
Tellurides - the telluride anion is Te2-
hedleyite
kanatzidisite
maslovite
michenerite
tellurobismuthite
pilsenite
volynskite
Bismuthides - the bismuthide anion is Bi3-
insizwaite
sobolevskite
Tellurobismuthides - bismuthides where tellurium replaces some bismuth
kotulskite
moncheite
montbrayite
Oxides - the oxide anion is O2-
bismite
bismutocolumbite
bismutotantalite
mambertiite
oxybismutomicrolite
sardignaite
sillénite
sphaerobismoite
uranosphaerite
Chlorides - the chloride anion is Cl-
bismoclite
Carbonates - the carbonate anion is (CO3)2-
beyerite
bismutite
kettnerite
Sulphates - the sulphate anion is (SO4)2-
aiolosite
elasmochloite
markhininite
Selenites - the selenite anion is (SeO3)2-
favreauite
Tellurates - salts of telluric acid H6Te6+O6
montanite
Tellurites - the tellurite anion is (Te4+O3)2-
bodieite
yecoraite
Phosphates - the phosphate anion is (P5+O4)3-
brendelite
mrázekite
petitjeanite
phosphowalpurgite
waylandite
Arsenates - the arsenate anion is (As5+O4)3-
asselbornite
atelestite
juanitaite
mixite
paganoite
preisingerite
rooseveltite
tetrarooseveltite
walpurgite
Vanadates - the vanadate anion is (V5+O4)3-
dreyerite
namibite
pucherite
schumacherite
Molybdates - the molybdate anion is (Mo6+O4)2-
koechlinite
Tungstates - the tungstate anion is (WO4)2-
russellite
Nesosilicates - insular (Si4+O4)4- groups
eulytine
Phyllosilicates - (Si4+2O5)2- groups
bismutoferrite
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