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Formula: HgS
Sulphide
Crystal System: Trigonal
Specific gravity: 8.176 measured, 8.20 calculated
Hardness: 2 2½
Streak: Red
Colour: Red
Solubility: Insoluble in hydrochloric acid, sulphuric and nitric acid
Environments:
Metamorphic environments
Hydrothermal environments
Fumeroles and Hot Spring deposits
Cinnabar occurs in the oxidation zone of epithermal (low temperature) hydrothermal veins, at fumeroles, and
also in hot springs.
It may be associated with
baryte,
native mercury,
pyrite,
marcasite,
opal,
quartz,
realgar,
stibnite, and sulphides of copper.
Cinnabar is the most important ore of mercury but is found in
quantity at comparatively few locations. It often forms twins with a shape reminiscent of a drill bit.
Localities
At Tongren, Guizhou, China, cinnabar occurs as deep red crystals on snowy white
dolomite
(AESS).
Cinnabar from Tongren - Image
At Fenghuang County, Xiangxi, Hunan, China, cinnabar occurs as fine red crystals, sometimes twinned, on a
dolomite matrix
(AESS).
Cinnabar from Fenghuang County - Image
At Charcas, Charcas Municipality, San Luis Potosí, Mexico,
the primary minerals are
sphalerite, galena,
chalcopyrite, bornite,
tetrahedrite,
arsenopyrite, pyrite and
silver minerals such as jalpaite,
diaphorite and acanthite. In
the host rock, as metamorphic or alteration minerals, danburite,
datolite, hedenbergite,
epidote, chlorite,
andradite, actinolite
and wollastonite have been reported.
Quartz, calcite and
danburite crystallised during the entire life of the systems, throughout
the intrusive emplacement, metamorphism, and mineralising events. With depth, both
sphalerite and galena decrease
while chalcopyrite increases.
Secondary sulphides formed include
bornite, covellite,
digenite and chalcocite.
Native silver, native gold,
hematite and goethite were
deposited after the sulphides
(Minrec 55.6.727-728).
Cinnabar was recorded as a new find in the 1960s in crystals to 1 cm resting on white
calcite
(Minrec 55.6.744-745).
Cinnabar from Charcas - Image
At the Mariquita Mine (Sultana Mine), Usagre, Badajoz, Extremadura, Spain, cinnabar was the main ore mineral;
very rarely it forms euhedral to subhedral crystals, but usually it is dipersed in the matrix or forms cleavable
masses, occasionally large, with a rich and beautiful vermilion colour, associated with
calcite or baryte. The mineral is
also found as small masses, grains and rough crystals included in baryte and
quartz. Supergene,
brick-red and pulverulent cinnabar, possibly formed from the decomposition of
tetrahedrite-(Hg) or earlier
mercury minerals, has also been found
(MinRec 55.4.496).
Cinnabar from the Mariquita Mine -
Image
At the Rutland Cavern, Heights of Abraham, Matlock Bath, Derbyshire, England, UK, cinnabar has been found
associated with
smithsonite, and as minute specks dusting the surface of both
smithsonite and fluorite
(RES p51).
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