Domeykite

Domeykite is a copper , Cu3As. It crystallizes in the isometric system, although crystals are very rare. It typically forms as irregular masses or botryoidal forms. It is an opaque, white to gray (weathers brassy) metallic mineral with a Mohs hardness of 3 to 3.5 and a specific gravity

It was first described in 1845 in the Algodones mines, Coquimbo , Chile mineralogist (1802–1889) by Wilhelm Haidinger