mineral

Polished quartz crystal specimen

Quartz, silicon dioxide (SiO₂), likely rock crystal or milky quartz

AI-generated identification · may be incorrect

Colorless to pale gray, vitreous luster, translucent, and apparently faceted or polished into a cabochon-like piece. Quartz has Mohs hardness 7, no cleavage, conchoidal fracture, trigonal crystal structure, and specific gravity about 2.65.

Identified September 16, 2026More mineral →

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Physical properties

Formation & geological history

Quartz forms from silica-rich hydrothermal fluids, igneous melts, or sedimentary veins; most specimens are Precambrian to Phanerozoic in age. The pictured piece appears human-shaped, polished, or cut rather than naturally crystal-faced.

Uses & applications

Used in glass, electronics, abrasives, countertops, and ornamental objects; clear attractive pieces are sold as inexpensive decorative stones or jewelry components.

Geological facts

The strong internal reflective bands may be healed fractures, growth zoning, or polishing facets; they are not enough to confirm a rarer gemstone such as diamond or sapphire.

Field identification & locations

Identify quartz by its glassy appearance, hardness, lack of cleavage, and ability to scratch ordinary glass. Common sources include Brazil, Madagascar, Arkansas, and worldwide hydrothermal veins.