mineral

Clear Quartz (Rock Crystal)

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 July 1, 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

Formed from cooling silica-rich magma or precipitation from hydrothermal veins. It is found in almost all geological environments and can be billions of years old.

Uses & applications

Used in electronics (oscillators), manufacturing of glass and ceramics, as gemstones in jewelry, and widely collected as metaphysical or decorative specimens.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Pure quartz is traditionally called rock crystal or clear quartz and was once believed by ancient Greeks to be permanently frozen ice.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and hexagonal crystal habit (if not tumbled). Common in quartz veins and as a primary constituent of granitic rocks.