Cuprite: Difference between revisions

Cuprite
Cuprite
	Cuprite from Morenci, Arizona
General
Category	Oxide mineral
Formula; (repeating unit)	Cu2O
IMA symbol	Cpr
Strunz classification	4.AA.10
Dana classification	4.1.1.1
Crystal system	Cubic
Crystal class	Hexoctahedral (m3m) ; H-M symbol: (4/m 3 2/m)
Space group	Pn3m
Unit cell	a = 4.2685 Å; V = 77.77 Å3; Z = 2
Identification
Color	Dark red to cochineal red, sometimes almost black
Crystal 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 scale hardness	3.5 to 4
Luster	Adamantine, sub-metallic, earthy
Streak	Shining metallic brownish-red
Diaphaneity	Transparent, translucent
Specific gravity	6.14
Optical properties	Isotropic
Refractive index	n = 2.849
Pleochroism	Visible
References

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Cuprite is an oxide mineral composed of copper(I) oxide Cu₂O, and is a minor ore of copper.^[5]

Cuprite from Tsumeb Mine (size:2.3 x 2.1 x 1.2 cm

Its dark crystals with red internal reflections are in the isometric system hexoctahedral class, appearing as cubic, octahedral, or dodecahedral forms, or in combinations. Penetration 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 Ancient Greek: χαλκός θρίξ τριχός, "plush copper ore")^[5] variety typically shows greatly elongated (parallel to [001]) capillary or needle like crystals forms.

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.^[6] 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.^[5]^[3]

Cuprite is found in the Ural Mountains, Altai Mountains, and Sardinia, and in more isolated locations in Cornwall, France, Arizona, Chile, Bolivia, and Namibia.^[7]

As a gemstone

Though almost all crystals of cuprite are far too small to yield faceted gemstones, one unique deposit from Onganja in Seeis, Namibia, which was discovered in the 1970s, has produced crystals which were both large and gem quality. Virtually every faceted stone over one carat (0.2 g) in weight is from this single deposit, which has long since been mined out. The number of faceted gems over two carats (0.4 g) is difficult to estimate, but according to Joel Arem, one-time curator for the Smithsonian National Gem and Mineral Collection in Washington, D.C., faceted cuprite of any size is considered one of the most collectible and spectacular gems in existence, with its deep garnet coloring and higher brilliance than a diamond. Only the gem's soft nature prevents it from being among the most valuable jewelry stones.

References

^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
^ "Cuprite". Mindat. Retrieved 2010-07-10.
^ ^a ^b "Cuprite". Webmineral data. Retrieved 2010-07-10.
^ Handbook of Mineralogy
^ ^a ^b ^c Spencer, Leonard James (1911). "Cuprite" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 12 (11th ed.). Cambridge University Press. p. 635.
^ Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., Wiley, p. 299-300 ISBN 0-471-80580-7
^ Joel E. Arem, Ph.D., F.G.A., Color Encyclopedia of Gemstones, 1977, Van Nostrand Reinhold Company

[1] Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.

[Mindat-2] "Cuprite". Mindat. Retrieved 2010-07-10.

[Webmin-3] "Cuprite". Webmineral data. Retrieved 2010-07-10.

[Handbook-4] Handbook of Mineralogy

[EB1911-5] Spencer, Leonard James (1911). "Cuprite" . In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 12 (11th ed.). Cambridge University Press. p. 635.

[Hurlbut-6] Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., Wiley, p. 299-300 ISBN 0-471-80580-7

[7] Joel E. Arem, Ph.D., F.G.A., Color Encyclopedia of Gemstones, 1977, Van Nostrand Reinhold Company

[1]

[2]

[3]

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[7]

@@ Line 1: / Line 1: @@
+{{Short description|Oxide mineral}}
 {{Infobox mineral
 | name        = Cuprite
 | category    = [[Oxide mineral]]
 | boxwidth    =
-| boxbgcolor  =
+| boxbgcolor  =#982e27
+| boxtextcolor = #fff
 | image       = CupriteUSGOV.jpg
-| imagesize   =
 | alt         =
-| caption     = Cuprite from Morenci, Arizona
+| caption     = Cuprite from [[Morenci, Arizona]]
-| formula     = Cu<SUB>2</SUB>O
+| 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>
-| strunz      = 04.AA.10
-| dana        = 4.1.1.1
-| symmetry    = [[Cubic (crystal system)|Cubic]] (4/m {{overline|3}} 2/m)
-| unit cell   = a = 4.2685 Å; V 77.77 Å³; Z = 2
 | molweight   =
+| strunz      = 4.AA.10
-| color       = Dark red to conchineal red, sometimes almost black
+| 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
-| system      = Cubic hexoctahedral
-| twinning    = Penetration twins
 | cleavage    = Fair in four directions forming octahedrons
 | fracture    = Conchoidal to uneven
@@ Line 48: / Line 51: @@
 }}
-'''Cuprite''' is an [[oxide mineral]] composed of [[copper(I) oxide]] Cu<sub>2</sub>O, and is a minor [[ore]] of [[copper]].
+'''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 a brittle to conchoidal fracture. The luster is sub-metallic to brilliant adamantine. The "chalcotrichite" variety typically shows greatly elongated (parallel to [001]) capillary or needle like  crystals forms.
+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.
+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 in 1845 and the name derives from the [[Latin]] ''cuprum'' for its copper content.<ref name=Webmin/>
+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]].
+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>
+== As a gemstone ==
-<ref>Joel E. Arem, Ph.D., F.G.A., <i>Color Encyclopedia of Gemstones</i>, 1977, Van Nostrand Reinhold Company</ref>
+Though almost all crystals of cuprite are far too small to yield faceted [[gemstone]]s, one unique deposit from Onganja in [[Seeis]], [[Namibia]], which was discovered in the 1970s, has produced crystals which were both large and gem quality. Virtually every faceted stone over one carat (0.2 g) in weight is from this single deposit, which has long since been mined out. The number of faceted gems over two carats (0.4 g) is difficult to estimate, but according to Joel Arem, one-time curator for the [[Smithsonian]] [[National Gem and Mineral Collection]] in [[Washington, D.C.]], faceted cuprite of any size is considered one of the most collectible and spectacular gems in existence, with its deep garnet coloring and higher brilliance than a diamond. Only the gem's soft nature prevents it from being among the most valuable jewelry stones.
-<b>Cuprite as a gemstone</b>
-Though almost all crystals of cuprite are far too small to yield faceted [[gemstones]], one unique deposit from Onganja, [[Southwest Africa]], which was discovered in the 1970s, has produced crystals which were both large and gem quality.  Virtually every faceted stone over one carat (200&nbsp;mg) in weight is from this single deposit, which has long been mined out. The number of faceted gems over two carats (400&nbsp;mg) is difficult to estimate, but according to Joel Arem, one-time curator for the [[Smithsonian]] [[National Gem and Mineral Collection]] in [[Washington DC]], faceted cuprite of any size is considered one of the most collectible and spectacular gems in existence, with its deep garnet coloring and higher brilliance than a diamond.  Only the gem's soft nature prevents it from being among the most valuable jewelry stones.
 ==See also==
 *[[Bornite]]
 *[[Tennantite]]
+*[[Tenorite]] CuO
 *[[Tetrahedrite]]
 ==References==
+{{Wiktionary}}
 {{Reflist}}
-[[Category:Copper minerals]]
+[[Category:Copper ores]]
 [[Category:Alchemical substances]]
 [[Category:Oxide minerals]]
 [[Category:Cubic minerals]]
+[[Category:Minerals in space group 224]]
+[[Category:Luminescent minerals]]
-[[ca:Cuprita]]
+[[Category:Minerals described in 1845]]
-[[cs:Kuprit]]
-[[de:Cuprit]]
-[[et:Kupriit]]
-[[es:Cuprita]]
-[[fa:کوپریت]]
-[[fr:Cuprite]]
-[[gl:Cuprita]]
-[[id:Kuprit]]
-[[it:Cuprite]]
-[[he:קופריט]]
-[[kk:Куприт]]
-[[lt:Kupritas]]
-[[hu:Kuprit]]
-[[nl:Cupriet]]
-[[ja:赤銅鉱]]
-[[pl:Kupryt]]
-[[pt:Cuprita]]
-[[ro:Cuprit]]
-[[ru:Куприт]]
-[[sk:Kuprit]]
-[[fi:Kupriitti]]
-[[uk:Куприт]]
-[[zh:赤銅礦]]