mineral

Milky quartz with iron-oxide staining

Quartz, silicon dioxide (SiO₂), likely massive milky quartz

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent, vitreous-to-waxy luster, irregular fracture, no obvious cleavage, and typical quartz density around 2.65 g/cm³. The yellow-brown patches are likely limonite/goethite staining or minor inclusions.

Identified August 12, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids crystallize in fractures and veins, commonly in granitic or metamorphic terrain; its age depends on the host rock, often Paleozoic to Precambrian. Weathering can expose and round the specimen.

Uses & applications

Used for decorative stone, lapidary work, carvings, and quartz products; opaque milky pieces have limited jewelry value but can be attractive cabinet specimens.

Geological facts

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

Field identification & locations

Identify by its glassy appearance, lack of cleavage, white translucency, and ability to scratch ordinary glass; a steel file should not scratch it. Common worldwide, especially in quartz veins and granite regions.