mineral

Clear quartz crystals

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Typically colorless to milky, vitreous luster, hexagonal crystal system, and conchoidal fracture; Mohs hardness 7, no true cleavage, specific gravity about 2.65. The pieces appear rough, translucent, and likely naturally terminated or broken quartz.

Identified September 8, 2026More mineral →

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Physical properties

Formation & geological history

Forms from silica-rich hydrothermal fluids, cavities in igneous rocks, and sedimentary or metamorphic veins; quartz is geologically widespread and occurs from Precambrian to modern settings.

Uses & applications

Used for glass, ceramics, abrasives, electronics, optical instruments, and collectors’ specimens; clear gem-quality quartz is also cut for jewelry.

Geological facts

Quartz is one of Earth’s most abundant minerals and commonly forms six-sided prisms with pyramidal terminations, though these small pieces appear irregular.

Field identification & locations

Identify by hardness—quartz scratches ordinary glass—plus its glassy luster, lack of cleavage, and six-sided crystal habit. Common localities include Brazil, Madagascar, Arkansas, the Alps, and many quartz veins worldwide.