Arsenopyrite
Arsenopyrite
A monoclinic mineral, 8[FeAsS]; pseudo-orthorhombic, prismatic, and metallic silver-white to steel gray; the most common arsenic mineral and principal ore of arsenic; occurs in many sulfide ore deposits, particularly those containing lead, silver, and gold.; arsenical pyrite; white pyrite; white mundic.
The mineral group arsenopyrite, glaucodot, gudmundite, osarsite, and ruarsite