Tenorite

Chemical compound

Tenorite is a copper oxide mineral with the chemical formula CuO. Wikipedia

Crystal system: Monoclinic

Color: Steel-gray, iron-gray, black

Chemical formula: CuO

Crystal class: Prismatic (2/m); (same H-M symbol)

Crystal habit: Lathlike crystals, curved, scaly, dendritic; commonly pulverulent, earthy, massive

Formula (repeating unit): CuO

Mohs scale hardness: 3.5–4