mineral
Smoky quartz
Quartz (SiO₂), likely smoky variety
AI-generated identification · may be incorrectTranslucent gray-brown, vitreous luster, uneven to conchoidal fracture, and no obvious cleavage; hardness 7 on the Mohs scale, hexagonal crystal system, specific gravity about 2.65. The small, rounded specimen may be naturally worn or tumbled.
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Physical properties
Translucent gray-brown, vitreous luster, uneven to conchoidal fracture, and no obvious cleavage; hardness 7 on the Mohs scale, hexagonal crystal system, specific gravity about 2.65. The small, rounded specimen may be naturally worn or tumbled.
Formation & geological history
Forms when silica-rich fluids crystallize in veins, pegmatites, and cavities; its smoky color commonly results from natural radiation acting on trace aluminum. Quartz occurs in rocks of many ages.
Uses & applications
Used as a durable ornamental and jewelry stone, as well as in collecting; quartz is also important in glassmaking and electronics.
Geological facts
Quartz is one of Earth’s most abundant minerals and resists scratching by ordinary steel.
Field identification & locations
Look for glassy luster, hardness near 7, and conchoidal fracture; smoky quartz occurs worldwide, notably in Brazil, the Alps, and the United States. A photograph alone cannot confirm the variety.
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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