Editing Cuprite (section)

{{Short description|Oxide mineral}}
{{Infobox mineral
| name        = Cuprite
| category    = [[Oxide mineral]]
| boxwidth    = 
| boxbgcolor  =#982e27
| boxtextcolor = #fff
| image       = CupriteUSGOV.jpg
| alt         =
| caption     = Cuprite from [[Morenci, Arizona]]
| formula     = Cu<sub>2</sub>O
| IMAsymbol=Cpr<ref>{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}</ref>
| molweight   =
| strunz      = 4.AA.10
| dana        = 4.1.1.1
| system      = [[Cubic crystal system|Cubic]]
| class       = Hexoctahedral (m{{overline|3}}m) <br/>[[H-M symbol]]: (4/m {{overline|3}} 2/m)
| symmetry    = ''P''n{{overline|3}}m
| unit cell   = a = 4.2685&nbsp;Å; V = 77.77&nbsp;Å<sup>3</sup>; Z&nbsp;=&nbsp;2
| color       = Dark red to cochineal red, sometimes almost black
| colour      =
| habit       = Cubic, octahedral, and dodecahedral crystals; as hairlike capillary forms, earthy, compact granular and massive
| twinning    = Penetration twins 
| cleavage    = Fair in four directions forming octahedrons
| fracture    = Conchoidal to uneven
| tenacity    = Brittle
| mohs        = 3.5 to 4
| luster      = Adamantine, sub-metallic, earthy
| streak      = Shining metallic brownish-red
| diaphaneity = Transparent, translucent
| gravity     = 6.14
| density     =
| polish      =
| opticalprop = Isotropic
| refractive  = n = 2.849
| birefringence =
| pleochroism = Visible
| 2V          =
| dispersion  =
| extinction  =
| length fast/slow =
| fluorescence=
| absorption  =
| melt        =
| fusibility  =
| diagnostic  =
| solubility  =
| other       =
| alteration  =
| references  = <ref name=Mindat>{{cite web|url=http://www.mindat.org/min-1172.html|title=Cuprite|publisher=Mindat|accessdate=2010-07-10}}</ref><ref name=Webmin>{{cite web|url=http://www.webmineral.com/data/Cuprite.shtml|title=Cuprite|publisher=Webmineral data|accessdate=2010-07-10}}</ref><ref name=Handbook>[http://rruff.geo.arizona.edu/doclib/hom/cuprite.pdf Handbook of Mineralogy]</ref>
}}

'''Cuprite''' is an [[oxide mineral]] composed of [[copper(I) oxide]] Cu<sub>2</sub>O, and is a minor [[ore]] of [[copper]].<ref name=EB1911>{{cite EB1911 |wstitle=Cuprite |volume=12 |page=635 |first=Leonard James |last=Spencer |authorlink=Leonard James Spencer}}</ref>
[[File:Cuprite-66649.jpg|thumb|left|Cuprite from Tsumeb Mine (size:2.3 x 2.1 x 1.2 cm]]
Its dark crystals with red internal reflections are in the [[Cubic crystal system|isometric]] system hexoctahedral class, appearing as cubic, octahedral, or dodecahedral forms, or in combinations. Penetration [[Crystal twinning|twins]] frequently occur. In spite of its nice color, it is rarely used for [[jewelry]] because of its low [[Mohs hardness]] of 3.5 to 4. It has a relatively high [[specific gravity]] of 6.1, imperfect cleavage and is brittle to conchoidal fracture. The luster is sub-metallic to brilliant adamantine. The "chalcotrichite" (from <span title="chalkós thríx trichós">{{langx|grc|χαλκός θρίξ τριχός}}, "plush copper ore")</span><ref name=EB1911/> variety typically shows greatly elongated (parallel to [001]) capillary or needle like  crystals forms.
[[Image:Chalcotrichite.jpg|thumb|left|Chalcotrichite from Ray, Arizona]]
It is a secondary mineral which forms in the oxidized zone of copper sulfide deposits. It frequently occurs in association with [[native copper]], [[azurite]], [[chrysocolla]], [[malachite]], [[tenorite]] and a variety of [[iron oxide]] minerals.<ref name=Hurlbut>Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy,'' 20th ed., Wiley, p. 299-300 {{ISBN|0-471-80580-7}}</ref> It is known as ''ruby copper'' due to its distinctive red color.

Cuprite was first described by [[Wilhelm Karl Ritter von Haidinger]] in 1845 and the name derives from the [[Latin]] ''cuprum'' for its copper content.<ref name=EB1911/><ref name=Webmin/>

Cuprite is found in the [[Ural Mountains]], [[Altai Mountains]], and [[Sardinia]], and in more isolated locations in [[Cornwall]], [[France]], [[Arizona]], [[Chile]], [[Bolivia]], and [[Namibia]].<ref>Joel E. Arem, Ph.D., F.G.A., ''Color Encyclopedia of Gemstones'', 1977, Van Nostrand Reinhold Company</ref>