mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous; Crystal Structure: Trigonal (hexagonal prisms); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

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

Identified March 1, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Colorless/Transparent; Luster: Vitreous; Crystal Structure: Trigonal (hexagonal prisms); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal solutions or the cooling of magma. It can be found in igneous, metamorphic, and sedimentary environments across all geological ages, often in veins or geodes.

Uses & applications

Used in electronics (oscillators), optical instruments, glassmaking, abrasive blasting, and extensively in jewelry and gemstone carving.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the Greek word 'krustallos' meaning ice, as ancient Greeks believed it was ice that had frozen so hard it could never melt.

Field identification & locations

Identify in the field by its hexagonal crystal habit, lack of cleavage, and ability to scratch glass. Found globally, with significant deposits in Brazil, Madagascar, and the United States (Arkansas). Collectors look for clarity and undamaged terminations.