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Formula: Zn2Te3O8
Oxide, spiroffite group,
tellurium-bearing mineral
Crystal System: Monoclinic
Specific gravity: 5.57 calculated
Hardness: 2½
Streak: Dark green
Colour: Grey
Environments
Localities
The type locality, the Zhongshangou mine, Dongping Au-Te ore field, Shuiquangou Complex, Chongli District, Zhangjiakou,
Hebei, China, is one of the tellurium-bearing
gold deposits in the Dongping gold
orefield, an important gold producer in China. Many
tellurium oxysalts occur here as
secondary products of the co-oxidation of
calaverite and sulphides in
quartz-vein-type gold ores.
Zincospiroffite was accidentally discovered in one polished section of ore. It occurs in three aggregates of
crystallites covering an area of 400 to 4000 microns2. These aggregates contain micrometric grains of native
gold, also produced during the oxidation of an assemblage of
calaverite + sphalerite –
pyrite in quartz. One of the aggregates
is coated with hematite
(CM 42. 763-768).
Minerals associated with zincospiroffite include sphalerite,
pyrite, hematite,
gold, galena and
calaverite
(Mindat).
At the Upper dumps, North Star Mine, Mammoth, Tintic Mining District, Juab County, Utah, USA, fine crystals of
zincospiroffite occur with other tellurium species, generally on a
matrix of quartz. Specimens range from bundles of plates to single crystals. The
colour is also variable, with pink, green, tan and yellow examples known. Single crystals and crystal bundles can reach
3 mm in size
(MinRec 55.2.232).
Zincospiroffite from the Upper Dumps - Image
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