Tetra-auricupride . Picture size 2 mm. Collection and foto Thomas Witzke. Locality: Karabash, Ural, Russia — Photo: Thomas Witzke · CC BY-SA 3.0 de
Tetra-auricupride
The ordered tetragonal gold-copper alloy CuAu — a rare natural intermetallic in placer deposits.
Intro adapted from Wikipedia (CC BY-SA).
Tetra-auricupride is an IMA-recognized mineral species in the native element class, with the chemical formula CuAu.
Key properties: Mohs hardness 1.6; specific gravity 14.67; Metallic. Anisotropism: Weak, with colors from gray to light gray. R: (405) 44.6, (436) 46.8, (480) 50.3, (526) 55.8 luster.
IMA symbol Taur, IMA status: approved, named in 1982.
Found in mafic to ultramafic rocks that also contain platinum group elements.
It is found associated with Pyrrhotite, pyrite, chalcopyrite, gold, silver, platinum group minerals, magnetite, chromite, tremolite, diopside, serpentine, chlorite, epidote, apatite.
In allusion to the composition and symmetry.