mineral

Milky quartz

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent, vitreous-to-greasy luster, hexagonal crystal structure, and indistinct cleavage with conchoidal fracture. The specimen appears massive and fractured, consistent with milky quartz, though calcite is a possible visual alternative.

Identified August 8, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or igneous melts crystallize in veins and cavities; most examples range from Precambrian to recent. Common in granitic pegmatites, quartz veins, and metamorphic rocks.

Uses & applications

Used for glass, ceramics, engineered stone, abrasives, and silicon production; attractive pieces are collected or used decoratively. This rough specimen has modest commercial value.

Geological facts

Milky coloration results from microscopic fluid inclusions, fractures, or both scattering light. Quartz commonly forms six-sided prisms, but massive vein quartz may lack visible crystal faces.

Field identification & locations

Common worldwide, including Brazil, Madagascar, the United States, and alpine regions. A steel knife should not scratch it, while quartz or hardened steel can scratch glass; calcite would fizz weakly in dilute acid and is much softer.