mineral

Quartz

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, typically white or translucent with a vitreous to greasy luster, hexagonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Identified July 28, 2026More mineral →

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Physical properties

Hardness of 7 on the Mohs scale, typically white or translucent with a vitreous to greasy luster, hexagonal crystal system, conchoidal fracture with no true cleavage, specific gravity of 2.65.

Formation & geological history

Forms in a wide variety of geological environments, including igneous, metamorphic, and sedimentary rocks. It is a major constituent of granites and sandstones and precipitates out of hydrothermal veins.

Uses & applications

Used in electronics (oscillators), glassmaking, abrasive materials, gemstone carving, and optical instruments.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust, surpassed only by feldspar. Due to its piezoelectric properties, quartz crystals are used in watches and electronics to generate a precise frequency.

Field identification & locations

Easily identified in the field by its high hardness (scratches glass), lack of cleavage, and conchoidal fracture. Found worldwide in nearly all types of geological formations.