mineral

Milky quartz pebble

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Hardness 7 Mohs; white to translucent, vitreous-to-waxy luster, granular/massive crystal structure, no cleavage, conchoidal fracture, specific gravity about 2.65. The rusty patches likely represent iron-oxide staining or minor matrix minerals.

Identified August 27, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, or cooling igneous rocks; the cloudy appearance comes from microscopic fluid inclusions or defects. Quartz occurs from Precambrian rocks to the present in nearly all geological environments.

Uses & applications

Common milky quartz is used as a silica source for glass, ceramics, engineered stone, and abrasives; attractive pieces are sold as inexpensive display or lapidary material, though this specimen appears unpolished.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing an electrical charge under pressure. Milky quartz is generally less transparent and less valuable than clear, amethyst, or vividly colored varieties.

Field identification & locations

Identify it by its glassy sheen, lack of cleavage, hardness sufficient to scratch ordinary glass, and conchoidal fracture; it should not be scratched by a steel knife. Common worldwide in quartz veins, granite, pegmatites, and metamorphic rocks.