TENORITE
Tenorite is a blackish-colored copper oxide mineral
(CuO). It usually forms coatings resulting from oxidation of native
copper (Cu) or copper-bearing sulfide minerals. The typical
weathering/alteration sequence of exposed native copper is: cuprite to
tenorite to malachite. Tenorite typically is nonmetallic black to
metallic dark gray in appearance, and is moderately soft (H = 3.5 to 4).
Tenorite
(black) mixed with chrysocolla (blue) in copper ore (4.0 cm across) from
the Algomah Mine of northern Michigan. Tenorite and chrysocolla are the
major copper ore minerals at this mine.