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Formula: As4S4
Sulphide of arsenic; realgar alters
to pararealgar on exposure to light, and
primary pararealgar is also known (Mindat)
Crystal System: Monoclinic
Specific gravity: 3.52 measured
Hardness: 1 to 1½
Streak: Light yelloe
Colour: Light yellow to orange-brown
Environments:
Pararealgar occurs as an alteration product of realgar in
stibnite-bearing quartz veins; the alteration is typically
a result of exposure to light. Associated minerals include realgar,
stibnite, tetrahedrite,
arsenopyrite, duranusite,
arsenic, arsenolite,
sulphur, lepidocrocite and
pyrite
(HOM).
Localities
There are two co-type localities, Grey Rock mine, Truax Creek, Bridge River area, Lillooet Mining Division, and Mount Washington mine, Comox
District, Nanaimo Mining Division, both in British Columbia, Canada.
At Grey Rock mine, pararealgar occurs with stibnite and
realgar
(AM 66.1277).
At Mount Washington, minerals associated with pararealgar include realgar,
stibnite, tetrahedrite,
arsenopyrite, arsenic and
arsenolite
(AM 66.1277).
At the Palomo Mine, Huachocolpa District, Huancavelica Province, Huancavelica, Peru, pararealgar
pseudomorphs after realgar have been found
(Minrec 39.2.104).
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