mineral

Milky quartz

Quartz (silicon dioxide, SiO₂)

AI-generated identification · may be incorrect

Typically white to translucent with a vitreous luster, uneven fracture, and no cleavage; Mohs hardness 7, trigonal crystal structure, and specific gravity about 2.65. The specimen appears massive and somewhat weathered, with minor iron- or clay-stained inclusions.

Identified August 14, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich hydrothermal fluids or magmas crystallize in fractures and cavities, commonly in veins and granitic rocks. Quartz is found from Precambrian to modern geological settings, so a precise age cannot be determined from the image.

Uses & applications

Used in glass, ceramics, electronics, abrasives, and engineered stone; attractive pieces are sold as inexpensive mineral specimens. Common rough specimens generally have modest value.

Geological facts

Its cloudy appearance results from microscopic fluid inclusions, fractures, or mineral impurities rather than a different quartz composition. Quartz is piezoelectric and is one of Earth’s most abundant minerals.

Field identification & locations

Common worldwide, including Brazil, Madagascar, the United States, and alpine or hydrothermal veins. Identify it by hardness—scratching glass but not being scratched by a steel knife—and its glassy luster; avoid confusing it with calcite, which is softer and cleaves readily.