mineral
Smoky Quartz
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 (Mohs scale); Color: Brownish-grey, smoky yellow, to nearly black; Luster: Vitreous (glassy); Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
- Hardness
- 7 (Mohs scale)
- Color
- Brownish-grey, smoky yellow, to nearly black
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 (Mohs scale); Color: Brownish-grey, smoky yellow, to nearly black; Luster: Vitreous (glassy); Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65
Formation & geological history
Formed in igneous or metamorphic rocks like pegmatites and granites. The smoky color results from free silicon formed from silicon dioxide by natural irradiation of the crystal.
Uses & applications
Used in gemstone jewelry, ornamental carvings, clock oscillators, and for metaphysical collecting.
Geological facts
It is the national gem of Scotland, where it is known as 'Cairngorm.' The dark color is often stable but can fade if exposed to intense sunlight for long periods.
Field identification & locations
Identify by its translucent brownish 'smoke' color and glass-like luster. Commonly found in Brazil, Madagascar, and the USA (Colorado). Collectors look for clarity and depth of color.
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Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Tumbled granite
Granite, a coarse-grained felsic intrusive igneous rock
igneous
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous