Tenorite

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Tenorite
Copper black (tenorite) with azurite - Nizhne Tagilsk, Ural.jpg
Tenorite from Nizhne Tagilsk (Russia)
General and classification
other names

Copper black

chemical formula CuO
Mineral class
(and possibly department) 		Oxides
System no. to Strunz
and to Dana 		4.AB.10 ( 8th edition : IV / A.05)
02/04/03/01
Crystallographic Data
Crystal system monoclinic
Crystal class ; symbol monoclinic prismatic; 2 / m
Room group (no.) (No. 15)
Lattice parameters a  = 4.69  Å ; b  = 3.43 Å; c  = 5.14 Å
β  = 99.5 °
Formula units Z  = 4
Twinning along {011}
Physical Properties
Mohs hardness 3.5
Density (g / cm 3 ) 6.45
Cleavage imperfect
Break ; Tenacity uneven, mussel-like
colour steel gray to black
Line color brownish black
transparency opaque
shine Metallic luster

Tenorite , also outdated as copper black , black copper ore , melaconite , melaconite or chemically known as copper (II) oxide , is a rather rarely occurring mineral from the mineral class of oxides and hydroxides . It crystallizes in the monoclinic crystal system with the chemical formula CuO and forms elongated crystals up to 2 mm in length less often, more often it is powdery, coarse or massive. The mineral is gray-black in color, appears brown in transmitted light, gray with a golden cast in reflected light.

Etymology and history

The mineral was first found in 1841 by Semmola on Vesuvius in Italy . It was named after the Italian botanist Michele Tenore (1780–1861).

classification

In the Strunz system , tenorite is one of the oxides with a metal to oxygen ratio of 2: 1 and 1: 1. After the 8th edition, it forms a group together with Crednerite , Delafossite , McConnellite and Paramelaconite . In the 9th edition , it forms its own subgroup of oxides with a ratio of metal to oxygen of 1: 1 and small to medium-sized cations.

In the Dana system , it forms a separate subgroup of the simple oxides with a cation charge of 2+.

Varieties

A variety of tenorite in which the copper oxide is present as a colloid is geltenorite . The variety was found in Bisbee , Arizona, USA .

Education and Locations

Tenorite forms in the oxidative zone of copper deposits under hydrothermal conditions. More rarely, it can also form as a sublimation product in volcanoes. It is associated with cuprite , copper , chrysocolla , malachite and azurite , when formed under hydrothermal conditions also iron - manganese oxides, when formed as a sublimate with copper and alkali chlorides and cotunnite .

A large number of sites are known, but rarely in crystalline and pure form. Locations include Vesuvius and Etna in Italy, Cornwall and Lanarkshire in Great Britain, Río Tinto in Spain , Siegen , Daaden and Neubulach in Germany , Jáchymov in the Czech Republic , Bogoslovsk , Nizhni Tagil and Tolbatschik in Russia , Chuquicamata in Chile , Tsumeb in Namibia as well Copper Harbor , Darwin and Bisbee in the United States .

Crystal structure

Crystal structure of tenorite

Tenorite crystallizes in the monoclinic crystal system in the space group C 2 / c (space group no. 15) with the lattice parameters a  = 4.69  Å ; b  = 3.43 Å, c  = 5.14 Å and β = 99.5 ° as well as four formula units per unit cell .

See also

Individual evidence

  1. ^ A b c Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 184 .
  2. ^ New Dana Classification of Simple Oxides
  3. ↑ Geltenorite at mindat.org (English).

literature

  • Tenorite. In: JW Anthony et al: Handbook of Mineralogy. Volume 1, Tucson, Ariz. 1990, ISBN 0-9622097-0-8 , p. 101. (pdf)
  • Petr Korbel, Milan Novák: Encyclopedia of Minerals . Nebel Verlag, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 76 .

Web links

Commons : Tenorite  - collection of pictures, videos and audio files