mineral

Clear quartz crystal

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; colorless to milky-white, vitreous luster, hexagonal crystal structure, and no cleavage (conchoidal fracture). The elongated crystal shows prismatic faces and likely a naturally terminated point, though it may be chipped or lightly polished.

Identified August 14, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids or magma crystallize in cavities, veins, and hydrothermal environments; individual crystals can form over long periods from Precambrian to recent geological ages. Common localities include Brazil, Arkansas, Madagascar, China, and the Alps.

Uses & applications

Used in glass, electronics, watches, abrasives, and foundry materials; clear crystals are sold as decorative or metaphysical specimens and occasionally as faceting rough.

Geological facts

Quartz is piezoelectric, producing an electrical charge under pressure, which enables quartz timing devices. Its clarity and pointed termination are characteristic but not sufficient alone to establish locality.

Field identification & locations

Identify by its glassy luster, lack of cleavage, hexagonal prism habit, and ability to scratch ordinary glass; confirm with hardness and conchoidal fracture tests. Estimated value: $2–$15 for a small common crystal, or $20–$100+ if exceptionally clear, large, or well terminated.