Smoky Quartz
What is Smoky Quartz?
Smoky Quartz is a brownish-gray to black, translucent variety of quartz. It owes its color to natural irradiation, which causes the presence of aluminum impurities within the crystal lattice. The depth of color varies from nearly transparent to opaque black, depending on the intensity of the irradiation and the concentration of impurities. It is a relatively common gemstone, prized for its clarity and smoky appearance.
Optical Properties
- Refractive Index
- 1.544-1.553
- Birefringence
- 0.009
- Pleochroism
- Weak to distinct
- Optical Character
- uniaxial (+)
- Dispersion
- 0.013
Smoky Quartz Market Value Calculator
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Smoky Quartz Localities Map
See where Smoky Quartz is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Map preview
North ZoneCentral RidgeSouth Basin
Quick Facts
Physical Properties
- Color
- Brown, Gray, Black
- Hardness (Mohs)
- 7
- Density
- 2.65 g/cm³
- Streak
- White
Chemical Properties
- Chemical Formula
- SiO2
- Elements
- Silicon, Oxygen
Also Known As
Smoky QuartzSmoky TopazSmoky Citrine
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