Silver grey paxite associated to bluish grey koutekite from Mohawk Mine, Mohawk, Keweenaw County, Michigan, United States of America. Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY 4.0
Paxite
Paxite is an IMA-recognized mineral species in the sulfide class, with the chemical formula CuAs₂.
It crystallizes in the monoclinic crystal system (space group P2_1/c). It is a member of the Arsenopyrite structural group.
Key properties: Mohs hardness 3.5–4; specific gravity 5.4; Black streak; Metallic, tarnishing black. Anisotropism: Very strong; in pale gray-green and dark brown with violet tint luster.
IMA symbol Pax, IMA status: approved, named in 1961.
Found in hydrothermal calcite veins cutting diopside hornfels lenses, in pyroxene gneisses and mica schists. Probably a late-stage reaction product formed at the expense of novákite and arsenic below 130 ° C (Černý Důl mine.
It is found associated with Novákite, koutekite, arsenic, arsenolamprite, silver, löllingite, nickeline, chalcocite, skutterudite, bornite, chalcopyrite, tiemannite, clausthalite.
The name comes from the Latin pax, peace.