mineral

Quartz (Smoky Quartz variant)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Grayish-brown to translucent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Grayish-brown to translucent
Luster: Vitreous (glassy)

Identified May 20, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Grayish-brown to translucent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Quartz forms in a wide variety of environments, but distinct crystals typically form from cooling magma in igneous rocks like granite or from hydrothermal veins. Smoky varieties obtain their color from natural irradiation of aluminum impurities over geological time.

Uses & applications

Used in glassmaking, jewelry (as a gemstone), clocks, watches, and various electronics due to its piezoelectric properties. Large specimens are popular among collectors and for ornamental use.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz', which has ancient Slavic origins meaning 'hard'.

Field identification & locations

Identify in the field by its hardness (will scratch glass and steel), glassy luster, and curved (conchoidal) fracture surfaces rather than flat cleavage planes. It is found globally in regions with igneous or metamorphic outcrops.