mineral

Milky quartz (quartz crystal)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent, vitreous-to-waxy luster, typically hexagonal crystal structure, and poor/no cleavage with conchoidal fracture. The specimen appears cloudy and irregularly fractured, possibly naturally etched or partially crystalline.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or cooling igneous melts precipitate quartz in veins and cavities. Quartz is common from Precambrian to modern geological settings; age cannot be determined from appearance alone.

Uses & applications

Used for glass, silicon, abrasives, ceramics, and engineered stone; attractive transparent varieties are cut as gemstones. This rough specimen has modest decorative and educational value.

Geological facts

Cloudiness generally results from microscopic fluid inclusions, fractures, or mineral impurities. Quartz is one of Earth’s most abundant and chemically durable minerals.

Field identification & locations

Identify by its glassy luster, lack of cleavage, conchoidal fracture, and ability to scratch ordinary glass; it should not fizz in dilute acid. Common worldwide, especially in hydrothermal veins, pegmatites, and quartz-rich sedimentary rocks.