Cuprite

Big Photo

Namibia
35.31 carats
© Mineral Classics

Cuprite was first described in 1845 and the name derives from the Latin "cuprum" for its copper content.

Cuprite forms well-developed cubic crystals. It shows internal reflections of the deep garnet-red colour inside the almost black crystal. Cuprite has metallic luster and very high refractive index. Cuprite produces attractive cabochons and fine faceted stones, but it is very soft and brittle.

There are different types of stone which are dyed red and offered in the trade as cuprite.

Cuprite Gemstones by Colour

This table shows the variety of hues this gemstone can be found in. Click on a photo for more information.
 

Cuprite Gemstones by Size

This table shows distribution of Cuprite gemstone sizes that are listed on this site. This can give a good indication as to the general availability of this gemstone in different sizes.
Contributed photos
Lightest:0.24 cts
Heaviest:66.34 cts
Average:13.92 cts
Total photos:14
Do you have a larger Cuprite? Why not upload a photo?
0.24ct to 6.85ct6.85ct to 13.46ct13.46ct to 20.07ct20.07ct to 26.68ct26.68ct to 33.29ct33.29ct to 39.90ct39.90ct to 46.51ct46.51ct to 53.12ct53.12ct to 59.73ct59.73ct to 66.34ct
General Information
Chemical Formula
Cu
 
2
O
Michael O’Donoghue, Gems, Sixth Edition (2006)
More from other references
Photos of natural/un-cut material from mindat.org
Physical Properties of Cuprite
Mohs Hardness3.5 to 4
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Specific Gravity5.85 to 6.15
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Cleavage QualityDistinct
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
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FractureUneven
Arthur Thomas, Gemstones (2009)
Heat SensitivitySensitive to heat
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Optical Properties of Cuprite
Refractive Index2.849
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
Optical CharacterIsotropic
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
More from other references
DispersionNil
Arthur Thomas, Gemstones (2009)
Colour
Colour (General)Carmine-red
Walter Schumann, Gemstones of the world (2001)
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Causes of ColourRed, Band theory
W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011)
TransparencyTranslucent
Walter Schumann, Gemstones of the world (2001)
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LustreMetallic
Walter Schumann, Gemstones of the world (2001)
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Crystallography of Cuprite
Crystal SystemIsometric
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
More from other references
HabitCubes, octahedra or combinations of forms
Michael O’Donoghue, Gems, Sixth Edition (2006)
More from other references
Geological Environment
Where found:Occurs in the oxidized zones of copper deposits
Michael O’Donoghue, Gems, Sixth Edition (2006)
Further Information
Mineral information:Cuprite information at mindat.org
Significant Gem Localities
DR Congo
 
  • Lualaba
    • Kolwezi mining district
France
 
  • Auvergne-Rhône-Alpes
    • Rhône
      • Villefranche
        • Chessy-les-Mines
mindat.org
Namibia
 
  • Khomas Region
    • Windhoek Rural
      • Seeis
        • Onganja mining area
          • Helen Farm 235 (Hellen claim; Parzelle Hellen)
Gems, Sixth Edition, Michael O’Donoghue, 2006, p. 403
  • Oshikoto Region
    • Tsumeb
No reference listed
USA
 
  • Arizona
    • Cochise Co.
      • Mule Mts
        • Warren Mining District
[MinRec 12:303-304]
Copyright © Jolyon & Katya Ralph 1993-2019. Site Map. Locality, gem & photograph data are the copyright of the individuals who submitted them. For more information please contact the . Gemdat.org is an online information resource dedicated to providing free gemmological information to all.