mineral

Milky quartz (rough crystal fragment)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Translucent white to pale gray, vitreous-to-waxy luster, typically hexagonal crystal structure, and indistinct cleavage with conchoidal fracture. Mohs hardness 7; specific gravity about 2.65. The specimen appears naturally broken rather than polished.

Identified September 17, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, and igneous or metamorphic rocks. Quartz is extremely widespread and occurs from Precambrian rocks to modern hydrothermal deposits; age cannot be determined from the photograph.

Uses & applications

Used in glass, ceramics, electronics, abrasives, engineered stone, and as a common collecting mineral. Attractive clear pieces may be used ornamentally, though this cloudy fragment is unlikely to be gem quality.

Geological facts

Milky appearance is caused mainly by microscopic fluid inclusions and defects. Quartz does not have the smooth cleavage surfaces typical of calcite or feldspar.

Field identification & locations

Likely quartz if it scratches ordinary glass and does not react with dilute vinegar or hydrochloric acid. Common worldwide, especially in quartz veins, pegmatites, granite, and metamorphic terrains; a precise locality is needed for stronger identification.