Tenorite

Tenorite is a copper oxide mineral with the simple formula CuO.

Tenorite occurs in the weathered or oxidized zone associated with deeper primary copper sulfide orebodies. Tenorite commonly occurs with chrysocolla and the copper carbonates, azurite and malachite. The dull grey-black color of tenorite contrasts sharply with the often intergrown blue chrysocolla. Cuprite, native copper and Fe–Mn oxides also occur in this environment.