mineral

Milky quartz (quartz-rich rock fragment)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Typically white to translucent with a vitreous-to-waxy luster, uneven fracture, and no cleavage; Mohs hardness 7, trigonal crystal structure, and specific gravity about 2.65. The specimen appears massive and granular rather than showing distinct crystal faces.

Identified September 6, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, or igneous and metamorphic rocks; most examples are geologically ancient, commonly Paleozoic or older depending on host rock. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used for glass, ceramics, abrasives, engineered stone, and silicon production; attractive pieces are collected, though this rough fragment is generally low-value.

Geological facts

Milky appearance results from microscopic fluid inclusions, fractures, or mineral impurities scattering light. Quartz is one of Earth’s most abundant and chemically resistant minerals.

Field identification & locations

Identify by its glassy appearance, hardness, lack of cleavage, and ability to scratch ordinary glass; a steel blade should not scratch it. Common worldwide in quartz veins, granites, pegmatites, and metamorphic terrains.