Tenorite

Not to be confused with Tannerite.

Tenorite, sometimes also called Black Copper, is a copper oxide mineral with the chemical formula CuO. The chemical name is Copper(II) oxide or cupric oxide.

Tenorite
General
Category	Oxide mineral
Formula	CuO
IMA symbol	Tnr[1]
Strunz classification	4.AB.10
Crystal system	Monoclinic
Crystal class	Prismatic (2/m) (same H-M symbol)
Space group	C2/c
Unit cell	a = 4.6837(5) Å b = 3.4226(5) Å c = 5.1288(6) Å; β = 99.47°; Z = 4
Identification
Color	Steel-gray, iron-gray, black
Crystal habit	Lathlike crystals, curved, scaly, dendritic; commonly pulverulent, earthy, massive
Twinning	Common on {011}, forming stellate groups; lamellar
Cleavage	Poor to indistinct
Fracture	Conchoidal to uneven
Tenacity	Brittle; flexible and elastic in thin scales
Mohs scale hardness	3.5–4
Luster	Metallic to earthy
Streak	Black
Diaphaneity	Opaque, thin flakes transparent
Specific gravity	6.5
Optical properties	Biaxial (+)
Pleochroism	Distinct; light to dark brown
References	[2][3][4]

Occurrence

Tenorite with azurite from Nischne Tagilsk, Urals, Russia

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.^[2]

In addition to the hydrothermal, tenorite also occurs as a volcanic sublimate from Vesuvius, Campania, and Etna, Sicily, Italy. As a sublimate it occurs with copper chlorides, alkali chlorides and cotunnite.^[2] The Vesuvian sublimate occurrence was originally named melaconise or melaconite by F. S. Beudant in 1832.^[5]

Tenorite was named in 1841 after the Italian botanist Michele Tenore (1780–1861).^[4]

See also

• Cuprite Cu₂O
• List of minerals
• List of minerals named after people