- a mineral, originally thought to have been a diarsenide of cobalt, CoAs2, but which is actually a skutterudite rich in cobalt.
- a silver-white to greyish mineral consisting chiefly of cobalt arsenide with nickel in cubic crystalline form. It occurs in veins associated with silver, nickel, and copper minerals, and is an important ore of cobalt and nickel. Formula: (Co,Ni)As 3-x
