mineral
Smoky Quartz
Silicon Dioxide (SiO2)
Hardness of 7 on the Mohs scale, brownish-grey to almost black color, vitreous luster, trigonal crystal system, conchoidal fracture, specific gravity of 2.65
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Physical properties
Hardness of 7 on the Mohs scale, brownish-grey to almost black color, vitreous luster, trigonal crystal system, conchoidal fracture, specific gravity of 2.65
Formation & geological history
Formed from hydrothermal solutions or igneous and metamorphic rocks where natural irradiation of silicon dioxide containing trace aluminum impurities creates the brown color
Uses & applications
Used in jewelry, ornamental carvings, lapidary arts, and spiritual or metaphysical practices
Geological facts
The color in smoky quartz is caused by free silicon formed from silicon dioxide by natural radioactive sources in the surrounding rock
Field identification & locations
Identified by its characteristic brown-to-grey translucent appearance and hardness that scratches glass easily; commonly found in pegmatites worldwide
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Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
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Limonite / Goethite (Iron Ore Mineral nodule)
FeO(OH)·nH2O / FeO(OH)
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Schist
Schist
Metamorphic
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral