mineral

Quartz crystal cluster

Quartz, silicon dioxide (SiO₂), likely milky or inclusion-bearing quartz

AI-generated identification · may be incorrect

Mohs hardness 7; typically colorless to translucent white, with a vitreous luster and hexagonal crystal system. It has indistinct cleavage, conchoidal fracture, and specific gravity about 2.65; the specimen appears naturally fractured or clustered rather than gem-cut.

Identified September 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or groundwater precipitate in fractures, cavities, and pegmatites; individual crystals may grow over long periods, commonly from Paleozoic to Cenozoic host rocks depending on locality.

Uses & applications

Used for glass, engineered stone, electronics, abrasives, and optical components; clear attractive crystals are sold as display specimens, while high-clarity varieties may be cut as gemstones.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing an electrical charge under pressure. Its transparency and internal fractures can create attractive “ice-like” textures.

Field identification & locations

Identify by glassy luster, hardness sufficient to scratch ordinary glass, hexagonal crystal faces, and lack of strong cleavage; common localities include Brazil, Madagascar, Arkansas, and the Alps. Value is usually about $10-$75 for a common hand specimen, or $100-$500+ for large, exceptionally clear crystals.