mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 on the Mohs scale; Color: Colorless to transparent; Luster: Vitreous (glass-like); Crystal structure: Trigonal/Hexagonal prism; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

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

Identified March 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms in igneous, metamorphic, and sedimentary environments. Typically crystallizes from cooling magma or precipitates from hydrothermal veins. It can be found in geological formations ranging from billions of years old to relatively recent deposits.

Uses & applications

Used extensively in electronics (piezoelectric oscillators), glass manufacturing, and abrasives. High-quality specimens are used in jewelry, gemstone carving, and as decorative collector pieces.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, the Greeks believed clear quartz was deeply frozen ice that would never melt. It exhibits piezoelectricity, meaning it generates an electric charge when mechanical stress is applied.

Field identification & locations

Identify in the field by its hexagonal crystal shape, lack of cleavage, and ability to scratch glass but not being scratched by a steel file. Commonly found in Brazil, Arkansas (USA), and the Alps. Look for termination points and horizontal striations on the crystal faces.