Petzite

Petzite

Petzite with quartz - Sacarîmb, Nagyág, Romania
General
Category telluride mineral
Formula
(repeating unit)		 Ag3AuTe2
Strunz classification 02.BA.40a
Crystal system Cubic Gyroidal H-M Symbol (4 3 2)
Identification
Color Steel-gray to iron-black, commonly tarnished from bronze-yellow to sooty black; grayish white with a pale bluish tint in polished section
Crystal habit Granular to massive
Fracture Subconchoidal irregular
Tenacity Slightly sectile to brittle.
Mohs scale hardness 2.5 - 3
Luster Metallic
Streak Grayish black
Diaphaneity Opaque
Specific gravity 8.7 - 9.14
References [1][2][3]

The mineral petzite, Ag3AuTe2, is a soft, steel-gray telluride mineral generally deposited by hydrothermal activity. It forms isometric crystals, and is usually associated with rare tellurium and gold minerals, often with silver, mercury, and copper.

The name comes from chemist W. Petz, who first analyzed the mineral from the type locality in Săcărâmb, Transylvania, Romania in 1845. It was described by Wilhelm Karl Ritter von Haidinger in 1845 and dedicated to W. Petz who had carried out the first analyses.[1][2]

It occurs with other tellurides in vein gold deposits. It is commonly associated with native gold, hessite, sylvanite, krennerite, calaverite, altaite, montbrayite, melonite, frohbergite, tetradymite, rickardite, vulcanite and pyrite.[1]

Petzite forms together with uytenbogaardtite (Ag3AuS2) and fischesserite (Ag3AuSe2) the uytenbogaardtite group.

See also

References

  1. 1 2 3 http://rruff.geo.arizona.edu/doclib/hom/petzite.pdf Handbook of Mineralogy
  2. 1 2 http://webmineral.com/data/Petzite.shtml Webmineral.com
  3. ↑ http://www.mindat.org/min-3180.html Mindat.org
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