mineral

Quartz

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, vitreous luster, transparent to translucent, hexagonal crystal system, conchoidal fracture with no true cleavage, and specific gravity of 2.65.

Identified August 3, 2026More mineral →

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Physical properties

Hardness of 7 on the Mohs scale, vitreous luster, transparent to translucent, hexagonal crystal system, conchoidal fracture with no true cleavage, and specific gravity of 2.65.

Formation & geological history

Forms in a wide variety of geological environments including igneous, metamorphic, and sedimentary rocks, often crystallizing from silica-rich hydrothermal solutions or cooling magma.

Uses & applications

Used extensively in electronics, glassmaking, abrasives, gemstones, and ornamental items.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust, surpassed only by feldspar. Its piezoelectric properties make it essential for keeping time in watches and controlling frequencies in electronic equipment.

Field identification & locations

Easily identifiable in the field by its high hardness (scratches glass), lack of cleavage, and conchoidal fracture. Found worldwide in nearly every type of geological terrain.