Category Native elements Strunz classification 1.AA.10a | Formula(repeating unit) Cu3Au Dana classification 1.1.2.1 | |
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Crystal class Hexoctahedral (m3m)H-M symbol: (4/m 3 2/m) | ||
Auricupride is a natural alloy that combines copper and gold. Its chemical formula is Cu3Au. The alloy crystallizes in the Cubic crystal system and occurs as malleable grains or platey masses. It is an opaque yellow with a reddish tint. It has a hardness of 3.5 and a specific gravity of 11.5.
A variant called tetra-auricupride (CuAu) exists. Silver may be present resulting in the variety argentocuproauride (Cu3(Au,Ag)).
It was first described in 1950 for an occurrence in the Ural Mountains Russia. It occurs as low temperature unmixing product in serpentinites and as reduction "halos" in redbed deposits. It is most often found in Chile, Argentina, Tasmania, Russia, Cyprus, Switzerland and South Africa.
References
Auricupride Wikipedia(Text) CC BY-SA