mineral

Quartz

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, vitreous to greasy luster, transparent to opaque, white streak, conchoidal fracture, and hexagonal crystal system.

Identified July 28, 2026More mineral →

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Physical properties

Hardness of 7 on the Mohs scale, vitreous to greasy luster, transparent to opaque, white streak, conchoidal fracture, and hexagonal crystal system.

Formation & geological history

Formed in a wide variety of geological environments, including igneous, metamorphic, and sedimentary rocks. Often crystallizes from hydrothermal solutions or silica-rich magmas.

Uses & applications

Used in glassmaking, electronics, oscillators, abrasives, gemstones, and ornamental objects.

Geological facts

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

Field identification & locations

Identified easily by its characteristic conchoidal fracture, lack of cleavage, and hardness that can scratch glass. Found worldwide in almost all rock types.