mineral

Milky quartz

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Typically hardness 7 Mohs, white to translucent, with a vitreous-to-waxy luster and no true cleavage; it has hexagonal crystal structure, though this piece appears broken or roughly shaped. The cloudy appearance comes from microscopic fluid inclusions, fractures, or mineral impurities.

Identified September 1, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins, pegmatites, and igneous or metamorphic rocks when silica-rich fluids crystallize. Quartz is common throughout geologic time; the specimen’s exact age cannot be determined from the photograph.

Uses & applications

Used for glass, ceramics, abrasives, engineered stone, and electronics; attractive transparent pieces may be cut as gemstones, while milky fragments are mainly teaching or collection specimens.

Geological facts

Quartz is one of Earth’s most abundant minerals and is strongly resistant to weathering. It produces a white streak and can scratch ordinary steel or glass.

Field identification & locations

Likely quartz if it scratches glass, shows irregular fracture rather than cleavage, and has a white streak. Common worldwide, especially in quartz veins and granite pegmatites.