mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on the Mohs scale
Color: Colorless/Transparent
Luster: Vitreous (glass-like)

Identified March 23, 2026More mineral →

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Physical properties

Hardness: 7 on the Mohs scale; Color: Colorless/Transparent; Luster: Vitreous (glass-like); Crystal Structure: Hexagonal (Trigonal); Cleavage: None (Conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from the cooling of silica-rich magma or through hydrothermal activity in veins. It can occur in nearly all geological environments but is most prominent in igneous rocks like granite and pegmatites. Geological age ranges from billions of years to relatively recent formations.

Uses & applications

Used widely in glassmaking, electronics (piezoelectric properties for oscillators), and abrasives. High-clarity specimens are used in jewelry (faceting or cabochons) and as decorative metaphysical objects/collectibles.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. It possesses piezoelectricity, meaning it generates an electric charge when mechanical stress is applied. Famous 'Herkimer Diamonds' are actually double-terminated quartz crystals.

Field identification & locations

Identify by its ability to scratch glass, its six-sided crystal habit, and the presence of horizontal striations on the prism faces. Found globally, with massive deposits in Brazil, Arkansas (USA), and Madagascar.