mineral

Clear Quartz (Rock Crystal)

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Colorless/Transparent
Luster: Vitreous (glassy)

Identified March 20, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Forms in all types of geological environments but most commonly through the cooling of silica-rich magma or from hydrothermal veins. It can form at various geological ages from the Precambrian to recent times.

Uses & applications

Used widely in electronics (oscillators and clocks) due to piezoelectric properties, glassmaking, abrasives, and as semi-precious gemstones in jewelry and decorative carvings.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, the Greeks believed clear quartz was deeply frozen ice (krystallos) that would never melt.

Field identification & locations

Identify in the field by its distinct hexagonal prisms ending in pyramids, its inability to be scratched by a steel knife, and its lack of cleavage. Common locations include Brazil, Madagascar, and Arkansas, USA.

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