Tenorite
Current inventory: 0 gems
 

  
Tenorite was named in 1841 by Prof. Giovanni Semmola in honor of Italian botanist, Prof. Michele Tenore (1780-1861), Professor of Botany, University of Naples, Italy.

Discovered in 1841; IMA status: Valid (pre-IMA; Grandfathered)

Chemistry

Chemical Formula:

CuO 

Copper Oxide

Molecular Weight:

79.55 gm

Composition:

Copper

79.89 %

Cu

100.00 %

CuO

Oxygen

20.11 %

O

100.00 %

100.00 %

= TOTAL OXIDE

Classification

Mineral Classification:

Oxides

Strunz 8th Ed. ID:

4/A.05-10

Nickel-Strunz 10th Ed. ID:

4.AB.10

4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
A : Metal: Oxygen = 2:1 and 1:1
B : M:O = 1:1 (and up to 1:1.25); with small to medium-sized cations only

Related to:

Tenorite - Crednerite Series.

Varieties:

Geltenorite

Synonyms:

Black Copper, Black Oxide of Copper, Kupferschwärze, Melaconisa, Melaconise, Melaconite, Schwärzkupfer, Schwärzkupfererz

Crystal Data

Crystallography:

Monoclinic - Prismatic

Crystal Habit:

Lathlike crystals, flattened on [100], elongated along [011], to 2 mm; curved, scaly, dendritic; commonly pulverulent, earthy, massive. 

Twinning:

On {011}, contact plane, common, forming stellate groups; lamellar.

Physical Properties

Cleavage:

Poor/indistinct in zone [011]

Fracture:

Irregular/uneven, conchoidal

Tenacity:

Brittle; flexible and elastic in thin scales

Moh's Hardness:

3.5 - 4.0; Vickers: VHN₁₀₀=190-300 kg/mm²  

Density:

6.45 - 6.50 (g/cm³)

Luminescence:

None

Radioactivity:

Not Radioactive

Optical Properties

Color:

Black, steel gray

Transparency:

Opaque; translucent on very thin edges

Luster:

Metallic

Refractive Index:

2.10 - 2.11  Biaxial ( ? )

Birefringence:

Anisotropic

Dispersion:

n/a

Pleochroism:

Weak; X = light brown, Z = dark brown

Anisotropism:

Strong: blue to gray; bireflectance: strong, light gray with golden hint

Occurances

Geological Setting:

In the oxidized zone of copper deposits, also as volcanic sublimate.

Common Associations:

Azurite, Chrysocolla, Copper, Cuprite, Malachite, Fe–Mn oxides (hydrothermal); Alkali Chlorides, Copper Chlorides, Cotunnite (volcanic).

Common Impurities:

None

Type Locality:

Vesuvio (Vesuvius), Napoli, Campania, Italy

Year Discovered:

1841

View mineral photos:

Tenorite Mineral Photos and Locations

Unusual Gem Categories

Black Gems

More Information

Mindat.org
Webmineral.com

Tenorite is a rare secondary copper oxide mineral that is rarely faceted. It is one of those gems for "black gem" collectors. It is usually opaque black with a metallic luster and fairly soft. Large, pure crystals for faceting are rare and typically found only as thin (2mm), scaley, lathlike crystals. Most locations produce Tenorite mixed with Azurite and Malachite. A recent find at the L'Etoile du Congo Mine (Star of the Congo Mine) and the Kalukuluku Mine, Lubumbashi (Elizabethville), Shaba, Congo (Zaïre) has produced some larger, pure crystals.

Although Tenorite is cited as being discovered in 1841 in Vesuvio (Vesuvius), Napoli, Campania, Italy, it was first referrenced by Abraham Gottlob Werner (1749-1817) in 1789 as Kupferschwärze, which means black copper in German. Tenorite was named in 1841 by Prof. Giovanni Semmola in honor of Italian botanist, Prof. Michele Tenore (1780-1861), Professor of Botany, University of Naples, Italy.

Tenorite distribution: many localities, but few for well-crystallized or pure material. From Vesuvius, Campania, and Etna, Sicily, Italy. In England, at a number of mines in Gwennap, Redruth, St. Just, and elsewhere in Cornwall. At Leadhills, Lanarkshire, Scotland. From Rio Tinto, Huelva Province, Spain. In Germany, at Siegen, Westphalia; from Daaden, Rhineland-Palatinate; and at Neubulach, Black Forest. At Jáchymov (Joachimsthal), Czech Republic. In Russia, from Bogoslovsk and Nizhni Tagil, Ural Mountains, and at the Tolbachik fissure volcano, Kamchatka Peninsula. In the USA, from Copper Harbor, Keweenaw County, Michigan; at Darwin, Inyo County, California; an ore at Bisbee, Cochise County, Arizona. From Chuquicamata, Antofagasta, Chile. At Tsumeb, Namibia.
 

  
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