mineral

Milky quartz (quartz-rich rock)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent, vitreous-to-greasy luster, nonmetallic, massive granular texture, and no visible cleavage (conchoidal fracture). Specific gravity is about 2.65; the specimen appears weathered and iron-stained in places.

Identified August 17, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed as a hydrothermal quartz vein or pegmatitic mass when silica-rich fluids crystallized in fractures, commonly during Precambrian to younger mountain-building events. Exact age and locality cannot be determined from the photograph.

Uses & applications

Used for glass, engineered stone, ceramics, abrasives, electronics, and ornamental specimens; opaque milky pieces have modest jewelry value.

Geological facts

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

Field identification & locations

Identify by its glassy sheen, hardness, lack of cleavage, and inability to scratch it with a steel knife while it can scratch ordinary glass; distinguish from calcite, which is softer and cleaves readily. Common worldwide in veins, granites, pegmatites, and metamorphic rocks.