mineral

Milky quartz

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7; white to translucent, vitreous-to-waxy luster, massive rather than visibly crystalline, with no cleavage and conchoidal fracture. The rounded shape suggests natural weathering or tumbling; surface staining may be iron oxide or soil.

Identified August 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or magma crystallize in veins and cavities, commonly in igneous and metamorphic rocks. Quartz is found in rocks of nearly all geological ages; this specimen’s exact age cannot be determined visually.

Uses & applications

Used in glass, ceramics, electronics, abrasives, and engineered stone; attractive milky pieces are collected or used decoratively. This small rough specimen has minimal commercial value.

Geological facts

Milky appearance results from microscopic fluid inclusions, fractures, or mineral impurities scattering light. It may be confused with calcite, but quartz is substantially harder and does not fizz in dilute hydrochloric acid.

Field identification & locations

Common worldwide, including Brazil, Madagascar, the United States, and many vein deposits. A steel knife should not scratch it, while quartz should scratch glass; avoid destructive testing on valuable pieces.