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

Tenorite - USGS Mineral Specimens 1083.jpg
A sample of tenorite
CategoryOxide mineral
(repeating unit)
Strunz classification4.AB.10
Crystal systemMonoclinic
Crystal classPrismatic (2/m)
(same H-M symbol)
Space groupC2/c
Unit cella = 4.6837(5) Å
b = 3.4226(5) Å
c = 5.1288(6) Å; β = 99.47°; Z = 4
ColorSteel-gray, iron-gray, black
Crystal habitLathlike crystals, curved, scaly, dendritic; commonly pulverulent, earthy, massive
TwinningCommon on {011}, forming stellate groups; lamellar
CleavagePoor to indistinct
FractureConchoidal to uneven
TenacityBrittle; flexible and elastic in thin scales
Mohs scale hardness3.5 - 4
LusterMetallic to earthy
DiaphaneityOpaque, thin flakes transparent
Specific gravity6.5
Optical propertiesBiaxial +
PleochroismDistinct; light to dark brown


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 FeMn oxides also occur in this environment.[1]

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.[1] The Vesuvian sublimate occurrence was originally named melaconise or melaconite by F. S. Beudant in 1832.[4]

Tenorite was named in 1841 after the Italian botanist Michele Tenore (1780–1861).[3]

See alsoEdit


  1. ^ a b c Handbook of Mineralogy
  2. ^ Webmineral data
  3. ^ a b Mindat
  4. ^ Chisholm, Hugh, ed. (1911). Encyclopædia Britannica (11th ed.). Cambridge University Press