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Formula: S
Native element, sulphur group, paramorph of
clinosulphur and rosickýite
Crystal System: Orthorhombic
Specific gravity: 2.07 measured, 2.076 calculated
Hardness: 2
Streak: White
Colour: Yellow, brownish yellow, greenish yellow
With a low melting point of 113 degrees C, sulphur burns readily in air, with a low
blue flame, and gives off choking fumes of sulphur-dioxide - acrid odour (forms
sulphurous and eventually sulphuric acid in air).
Solubility: Insoluble in water, hydrochloric, nitric and sulphuric acid
Common impurities: Se,Te
Environments:
Sedimentary environments
Volcanic sublimates
(common)
Most native sulphur is formed by reduction of sulphates, especially in salt domes, where it forms by
the bacterial
decomposition of calcium sulphate. It also often occurs at or near the crater rims of active or extinct volcanoes,
derived from volcanic gases and
associated with realgar and
cinnabar. The volcanic gases may produce sulphur as a direct
sublimation product
or by the incomplete oxidation of
hydrogen sulphide gas. In sedimentary rocks sulphur is most commonly associated with
anhydrite,
gypsum and limestone.
Localities
The Two Mile and Three Mile deposits, Paddy's River, Paddys River District, Australian Capital Territory, Australia,
are skarn deposits at the contact between
granodiorite and volcanic rocks.
sulphur is a secondary native element that occurs as
crystals up to 1 mm in limonite from the dump, and also associated with
copiapite. It can be seen forming as a breakdown product of
melanterite associated with oxidising
pyrite
(AJM 22.1.38).
At the Malo-Bystrinskoe lazurite deposit, Malaya Bystraya River Valley,
Slyudyanka, Lake Baikal area,
Irkutsk Oblast, Russia, sulphur is found with lazurite in
calcite
(FM 75879).
At the Ball Eye mine and quarry, Cromford, Derbyshire, England, UK, native sulphur has been reported with
anglesite in oxidised galena
(RES p74).
At Tsumeb, Namibia, sulphur has been found with schultenite,
anglesite and galena
(R&M 93.6.548).
At Cookes Peak mining district, Luna county, New Mexico, USA, sulphur is found in small cavities in oxidising
galena (R&M 94.3.236).
Alteration
chalcopyrite, arsenopyrite, CO2
and O2 to Fe-tennantite, siderite and
sulphur
10CuFeS2 + 4FeAsS + 4CO2 + 8O2 → Cu10Fe2As4S13 +
4Fe(CO3) + 11/2S2
(CM 28.725-738)
chalcopyrite, arsenopyrite and
sulphur to Fe-tennantite and
pyrite
10CuFeS2 + 4FeAsS + 13/2S2 → Cu10Fe2As4S13 + 12FeS2
This reaction occurs at a comparatively low temperature
(CM 28.725-738).
chalcopyrite, arsenopyrite and
sulphur to Fe-tennantite and
troilite
l0CuFeS2 + 4FeAsS + l/2S2 → Cu10Fe2As4S13 + l2FeS
(CM 28.725-738)
chalcopyrite, stibnite and
sulphur to Fe-tetrahedrite and pyrite
10 CuFeS2 + 2 Sb2S3 + 3/2 S2 → Cu10Fe2As4S13
+ 8FeS2
(CM 28.725-738)
covellite and ferric sulphate to ferrous sulphate, copper sulphate and sulphur
CuS + Fe2(SO4)3 → 2FeSO4 + CuSO4 + S
Covellite may be oxidised by the strong oxidising agent ferric sulphate
according to the above reaction to form
sulphur
(AMU/b3-3-7.htm).
enargite and pyrite to
Fe-tennantite, chalcopyrite and
sulphur
4Cu3AsS4 + 4FeS2 → Cu10Fe2As4S13 + 2CuFeS2
+ 7/2S2
(CM 28.725-738)
skinnerite to chalcocite,
antimony and sulphur
2Cu3SbS3 → 3Cu2S + 2Sb + 3/2S2
(CM 28.725-738)
stibnite and pyrite to
berthierite and sulphur
Sb2S3 + FeS2 → FeSb2S4 + l/2S2
(CM 28.725-738)
Fe-tetrahedrite, berthierite and
sulphur to chalcopyrite and
stibnite
Cu10Fe2Sb4S13 + 2FeSb2S4 + 11/2S2 → 10CuFeS2
+ 4Sb2S3
(CM 28.725-738)
Fe-tetrahedrite, siderite and
sulphur to chalcopyrite,
stibnite, CO2 and O2
Cu10Fe2Sb4S13 + 8Fe(CO3) + 13/2S2 → 10CuFeS2
+ 2Sb2S3 + 8CO2 + 4O2
(CM 28.725-738)
Zn-tetrahedrite to chalcocite,
antimony, sphalerite and
sulphur
Cu10Zn2Sb4S13 → 5Cu2S + 4Sb + 2ZnS + 3S2
(CM 28.725-738)
Zn-tetrahedrite to skinnerite,
antimony, sphalerite and
sulphur
3Cu10Zn2Sb4S13 → 10Cu3SbS3 + 2Sb + 6ZnS + 3/2S2
(CM 28.725-738)
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