mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

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

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

Identified March 21, 2026More mineral →

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Physical properties

Hardness: 7 on the 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 the cooling of silica-rich magma or through hydrothermal activity in veins and geodes. It can be found in a wide variety of geological environments ranging from igneous to metamorphic rocks, occurring across almost all geological ages.

Uses & applications

Used widely in electronics (oscillators), glass manufacturing, and abrasives. In jewelry, it is used for beads and faceted stones. It is also a staple in the mineral collecting and metaphysical communities.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, the Ancient Greeks believed clear quartz was fossilized ice that had frozen so hard it would never melt, hence the name 'krystallos' (ice).

Field identification & locations

Identify in the field by its hardness (will scratch glass and steel), hexagonal crystal habit, and shell-like (conchoidal) fracture pattern. It is common worldwide, with major commercial deposits in Brazil, Arkansas (USA), and Madagascar.