mineral

Milky quartz (quartz-rich rock)

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Typically white to gray, translucent to opaque, with a vitreous to waxy luster and massive crystalline texture; Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The specimen appears weathered and iron-stained, possibly containing minor feldspar or mica.

Identified September 11, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, or pegmatites, and commonly occurs in quartz-bearing igneous and metamorphic rocks. Quartz is geologically ancient and forms throughout Earth history.

Uses & applications

Used in glassmaking, ceramics, abrasives, engineered stone, electronics, and construction aggregate; attractive pieces are sold as cabinet specimens or lapidary rough. This irregular specimen has modest commercial value.

Geological facts

Quartz is one of Earth’s most abundant minerals and is piezoelectric, producing an electrical charge under pressure. Milky opacity results mainly from microscopic fluid inclusions, fractures, and structural defects.

Field identification & locations

Identify it by its hardness, lack of cleavage, pale color, and glassy fracture; it should scratch ordinary glass but not be scratched by a steel knife. Common worldwide in hydrothermal veins, granites, pegmatites, and metamorphic terrains.