Covellite


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Related to Covellite: Enargite

covellite

[kō′ve‚līt]
(mineralogy)
CuS An indigo-blue mineral of metallic luster that crystallizes in the hexagonal system; it is usually massive or occurs in disseminations through other copper minerals and represents an ore of copper. Also known as indigo copper.

Covellite

 

(named for its discoverer, the Italian chemist N. Covelli, 1790–1829), a mineral of the sulfide class. Chemical composition, CuS; it contains 66.48 percent Cu and 33.52 percent S. The structure of covellite has Cu+ and Cu2+ atoms, as well as the simple ion S2– and the paired ion S22–. The structural elements of Cu2+ surrounded by three S2– and Cu+ ions, which are in the centers of paired tetrahedrons connected by S22 ions, are located in layers and provide the perfect cleavage of covellite. Thus, the structurally regular formula for covellite will be (Cu2S#x00B7;CuS2). Crystals are very rare; secondary incrustations, as well as films on other sulfides or powdery masses that replace them, are common. The color is dark blue. Hardness on the mineralogical scale, 1.5–2.0; density, 4,590–4,670 kg/m3. Covellite is a typical mineral in the zone of secondary sulfide enrichment in the oxidized parts of sulfide copper deposits. It is used as a copper ore.

References in periodicals archive ?
Sulfides: galena, argentite, pyrite, tetrahedrite, chalcopyrite, bornite, arsenopyrite, and covellite
In the upper part of the orebody, which was mostly mined out by previous operators, the copper existed predominantly in cyanide soluble secondary copper minerals such as chalcocite, bornite and covellite.
Ore minerals include gold, silver, chalcopyrite (CuFeS2), galena (PbS), bornite (CuFeS4), covellite (CuS), chalcocite (Cu2S), anglesite (PbSO4), sphalerite (ZnS), argentite (Ag2S), cerussite (PbCO3) and smithsonite (ZnCO3).
Examination of thin sections from selected mineralized samples at the University of Alaska petrography lab confirms the presence of widespread pentlandite together with millerite and lesser covellite.
Removal of the waste rock revealed the presence of some extreme unexpected and unknown high grade copper and silver ores, such as the important copper ore mineral bornite, the beautiful crystal covellite, and the high yielding copper ore cuprite.
Hypogene sulphide mineralization consists of chalcopyrite, bornite, covellite and pyrite.
Pyrite, sphalerite and possible covellite occur with massive, banded and cockade textures and host rock clasts.
Mineralization consists of chalcopyrite and bornite with secondary covellite and chalcocite, hosted within gabbroic intrusive rocks associated with a major regional fault system.
The primary copper-bearing minerals occurring in the Moonlight deposit are bornite and chalcopyrite with lesser amounts of covellite and chalcocite.
In the last three months, 44 holes totalling approximately 7,300 metres were drilled to define the near-surface chalcocite blanket amenable to heap leach, SX-EW processing, and 77 holes totaling approximately 34,000 metres were completed to define the underlying covellite and chalcopyrite and gold zones.