mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

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

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

Identified June 26, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in igneous, metamorphic, and sedimentary environments through the cooling of magma or hydrothermal solutions. Found in pegmatites and veins. Geological age varies from billions of years to more recent formations.

Uses & applications

Used in jewelry, decorative ornaments, electronics (piezoelectric properties), glassmaking, and abrasive tools. Highly valued by crystal collectors and for metaphysical use.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Rock crystal' comes from the Greek word 'krystallos', meaning ice, as ancient Greeks believed it was permanently frozen water.

Field identification & locations

Identified by its crystal clarity, 6-sided hexagonal prisms, and ability to scratch glass. Found worldwide, with prominent deposits in Brazil, Madagascar, and Arkansas (USA). In the field, look for crystalline clusters in geode cavities or veins.