Clear Quartz (Rock Crystal)

Physical Properties

Hardness: 7 on Mohs scale. Color: Colorless/Transparent. Luster: Vitreous (glassy). Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

Formation & Geological History

Forms in a wide variety of environments, most commonly by the cooling of silica-rich magma or from hydrothermal veins. It is found in igneous, metamorphic, and sedimentary rocks across all geological ages.

Uses & Applications

Extensively used in electronics (oscillators), optics, glass making, abrasives, and as semi-precious gemstones in jewelry. It is also highly popular for ornamental carving and metaphysical collections.

Geological Facts

Quartz is the second most abundant mineral in Earth's continental crust. 'Rock crystal' comes from the Greek word 'krystallos', meaning ice, as Greeks believed it was ice frozen so hard it would never melt.

Field Identification & Locations

Identify by its ability to scratch glass, lack of cleavage, and transparent appearance. Commonly found in pegmatites, hydrothermal veins, and as river pebbles. Look for characteristic hexagonal prism shapes in undisturbed cavities.

Identified on: 4/13/2026

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