mineral

Milky quartz (likely quartz crystal fragment)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Mohs hardness 7; translucent white to pale gray, with vitreous to pearly luster and conchoidal fracture. It has a trigonal crystal structure and no cleavage; the rough, broken shape may obscure crystal faces. The brown coating may be iron-oxide staining or attached matrix.

Identified August 16, 2026More mineral →

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Physical properties

Formation & geological history

Quartz crystallizes from silica-rich hydrothermal fluids, pegmatites, or cavities in igneous and metamorphic rocks; milky inclusions commonly reflect microscopic fluids or fractures. Quartz formed throughout geological time, often from Precambrian to younger veins and cavities.

Uses & applications

Used extensively in glass, ceramics, abrasives, electronics, and engineered stone; attractive pieces are sold as inexpensive mineral specimens. This fragment has modest jewelry or lapidary potential unless it proves unusually clear or displays good crystal form.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing voltage under mechanical stress. It commonly forms six-sided prismatic crystals, though this specimen appears fractured or partly weathered.

Field identification & locations

Identify by its glassy appearance, hardness, lack of cleavage, and ability to scratch ordinary glass; it should not be confused with softer calcite. Common sources include Brazil, Madagascar, the United States, and worldwide quartz veins.