Smoky Quartz

Big Photo

Brazil
4.4 carats
© gemselect.com

Smoky quartz is named after its smoky colour. Colouring is caused by (natural and artificial) gamma rays. The colour of Smoky quartz is variable from brown to black and sometimes smoky grey.

Smoky Quartz Gemstones by Colour

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

Smoky Quartz Gemstones by Size

This table shows distribution of Smoky Quartz 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:0.67 cts
Heaviest:41.28 cts
Average:11.85 cts
Total photos:45
Do you have a larger Smoky Quartz? Why not upload a photo?
0.67ct to 4.73ct4.73ct to 8.79ct8.79ct to 12.85ct12.85ct to 16.91ct16.91ct to 20.98ct20.98ct to 25.04ct25.04ct to 29.10ct29.10ct to 33.16ct33.16ct to 37.22ct37.22ct to 41.28ct
General Information
A variety or type of:Quartz
Varieties/Types:
Morion - Sometimes synonymous with Smoky quartz, but often reserved for nearly black Smoky quartz.
Other Names/Trade Names:
Chemical Formula
SiO
 
2
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Smoky Quartz Treatments
May be produced by irradiation of rock crystal (not detectable with standard tests) - Blue Chart Gem Identification, Herve Nicolas Lazzarelli, 2010, p 7
Physical Properties of Smoky Quartz
Mohs Hardness7
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Specific Gravity2.65
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
TenacityBrittle
Walter Schumann, Gemstones of the world (2001) Very brittle
Cleavage QualityNone
Walter Schumann, Gemstones of the world (2001)
FractureConchoidal
Walter Schumann, Gemstones of the world (2001)
Optical Properties of Smoky Quartz
Refractive Index1.544 to 1.553
Herve Nicolas Lazzarelli, Blue Chart Gem Identification (2010)
Optical CharacterUniaxial/+
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Birefringence0.009
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
PleochroismDark: definite - brown, reddish-brown
Walter Schumann, Gemstones of the world (2001)
More from other references
Dispersion0.013
Walter Schumann, Gemstones of the world (2001)
Colour
Colour (General)Clear brown colour and varying from a light brown to dark a brown
Michael O’Donoghue, Gems, Sixth Edition (2006)
Causes of ColourSmokey, color center related to the Al3+ impurity.
W. William Hanneman, Pragmatic Spectroscopy For Gemologists (2011)
TransparencyTransparent,Translucent,Opaque
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
Fluorescence & other light emissions
Fluorescence (General)Usually none
Walter Schumann, Gemstones of the world (2001)
Crystallography of Smoky Quartz
Crystal SystemTrigonal
Ulrich Henn and Claudio C. Milisenda, Gemmological Tables (2004)
HabitHexagonal prisms
Walter Schumann, Gemstones of the world (2001)
Further Information
Mineral information:Smoky Quartz information at mindat.org
Significant Gem Localities
Bolivia
 
  • Santa Cruz
    • Ángel Sandoval Province
      • La Gaiba mining district
Laurs (2001, 2010)
Laurs (2001, 2010)
Brazil
 
  • Minas Gerais
    • Conselheiro Pena
      • Ferruginha
Macri et al. (2006)
Macri et al. (2006)
Kenya
 
  • Kitui County
Madagascar
 
  • Alaotra-Mangoro
Madagascar, extraLapis English No.1, 2001, p. 46
  • Atsimo-Atsinanana
Pezzotta (2001)
  • Betsiboka
    • Tsaratanàna District
      • Ambakireny
Madagascar, extraLapis English No.1, 2001, p. 43
  • Sava
    • Andapa District
Danet (2009)
Mozambique
 
  • Zambezia Province
    • Mulevala District
Bettencourt-Dias and Wilson (2000)
Myanmar
 
  • Mandalay Region
    • Pyin-Oo-Lwin District
      • Mogok Township
        • Bernardmyo
Ted Themelis (2008) Gems & mines of Mogok
        • Kyatpyin North
Ted Themelis (2008) Gems & mines of Mogok
Sri Lanka
 
  • Sabaragamuwa Province
    • Ratnapura District
      • Ratnapura
UK
 
  • Scotland
    • Highland
No reference listed
USA
 
  • California
    • San Diego County
      • Warner Springs Mining District
        • Warner Springs
  • North Carolina
    • Cleveland County
      • Shelby
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