mineral
Smoky Quartz
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on Mohs scale; Color: Brownish grey to black; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65
- Hardness
- 7 on Mohs scale
- Color
- Brownish grey to black
- Luster
- Vitreous (glassy)
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Physical properties
Hardness: 7 on Mohs scale; Color: Brownish grey to black; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65
Formation & geological history
Forms in igneous rocks (pegmatites) and metamorphic rocks. The dark color results from natural irradiation of trace aluminum impurities within the quartz crystal lattice.
Uses & applications
Used in gemstone manufacturing, jewelry, metaphysical collecting, and historically in the construction of early sunglasses in China.
Geological facts
The name 'smoky' is derived from its appearance, which looks like it is filled with smoke. Very dark, opaque varieties are specifically called 'morion'.
Field identification & locations
Identify by its smoky translucence, hexagonal habit, and lack of cleavage. Common in Brazil, Madagascar, and the Swiss Alps.
