mineral

Quartz

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, color ranges from clear/white to various shades of yellow, brown, or gray due to impurities, vitreous to greasy luster, trigonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Identified August 1, 2026More mineral →

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Physical properties

Formation & geological history

Forms in a wide variety of geological environments, most notably in igneous rocks like granite and pegmatites, hydrothermal veins, and as detrital grains in sedimentary rocks. Can form at various temperatures and pressures throughout geological time.

Uses & applications

Used in electronics (oscillators, quartz clocks), glassmaking, abrasive materials, foundry sand, gemstones, and ornamental carvings.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust, surpassed only by feldspar. It exhibits piezoelectric properties, meaning it can generate an electrical charge in response to applied mechanical stress.

Field identification & locations

Easily identifiable in the field by its characteristic hardness (scratches glass easily), lack of cleavage, conchoidal fracture, and glassy luster. Found worldwide in almost every geological setting.