mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Colorless and transparent. Luster: Vitreous (glass-like). Crystal Structure: Trigonal / Hexagonal. Cleavage: None (conchoidal fracture). Specific Gravity: ~2.65.

Hardness: 7 on Mohs scale
Color: Colorless and transparent
Luster: Vitreous (glass-like)

Identified July 26, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Colorless and transparent. Luster: Vitreous (glass-like). Crystal Structure: Trigonal / Hexagonal. Cleavage: None (conchoidal fracture). Specific Gravity: ~2.65.

Formation & geological history

Forms in igneous, metamorphic, and sedimentary geological environments, most commonly in pegmatites and hydrothermal veins as silica-rich fluids cool and crystallize.

Uses & applications

Widely used in gemstone jewelry, ornamental carvings, lapidary arts, and historically in electronics, optical equipment, and glassmaking.

Geological facts

Ancient Greeks believed rock crystal was ice that had been frozen so hard it could never melt. High-purity natural clear quartz is renowned for its optical clarity and piezoelectric properties.

Field identification & locations

Identify in the field by its hardness (scratches glass, cannot be scratched by a steel knife), glassy luster, and conchoidal fracture. Commonly found in quartz veins, pegmatites, and alluvial gravel deposits worldwide.