mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Colorless/Transparent, Luster: Vitreous (glassy), Crystal system: Hexagonal/Trigonal, Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Identified April 27, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Colorless/Transparent, Luster: Vitreous (glassy), Crystal system: Hexagonal/Trigonal, Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Formation & geological history

Forms in all types of environments (igneous, metamorphic, and sedimentary) through crystallization of silica-rich molten rock or hydrothermal veins. Found in formations of all geological ages.

Uses & applications

Used in electronics (oscillators), manufacturing of glass and ceramics, jewelry (gemstones), and as decorative collector 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 is often found in clusters of hexagonal prisms.

Field identification & locations

Identify by its six-sided prismatic habit, hardness (will scratch glass), and lack of cleavage. Commonly found in mountainous regions worldwide, including Arkansas (USA), Brazil, and the Alps.