mineral

Smoky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Brown to black (translucent), Luster: Vitreous (glassy), Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified June 19, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Brown to black (translucent), Luster: Vitreous (glassy), Crystal structure: Trigonal/Hexagonal, Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Forms in igneous rocks like granite and pegmatites, as well as metamorphic rocks. The smoky color is caused by natural irradiation of trace aluminum impurities within the crystal lattice.

Uses & applications

Used primarily in jewelry (as a gemstone), for ornamental carvings, as a collector specimen, and in holistic practices.

Geological facts

The dark color is often artificially enhanced by lab irradiation. Morion is the name given to very dark, nearly opaque black varieties of smoky quartz.

Field identification & locations

Look for a translucent brown appearance with a glassy luster and no cleavage. It often has shell-like (conchoidal) fracture marks on broken surfaces. Found worldwide in locations like Brazil, Madagascar, and the Swiss Alps.