mineral
Milky quartz cluster
Quartz (silicon dioxide, SiO₂)
AI-generated identification · may be incorrectWhite to translucent, glassy luster with irregular intergrown crystals; Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The specimen appears to be a rough quartz fragment, though the image alone cannot exclude calcite or another pale mineral.
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Physical properties
White to translucent, glassy luster with irregular intergrown crystals; Mohs hardness 7, no cleavage, conchoidal fracture, and specific gravity about 2.65. The specimen appears to be a rough quartz fragment, though the image alone cannot exclude calcite or another pale mineral.
Formation & geological history
Quartz commonly crystallizes from silica-rich hydrothermal fluids in veins, cavities, and igneous or metamorphic rocks. Individual specimens range widely in age, from recent cavity growth to Precambrian vein deposits.
Uses & applications
Used for glass, ceramics, electronics, abrasives, and engineered stone; attractive clusters are sold as inexpensive collector specimens and occasionally used decoratively.
Geological facts
Quartz is one of Earth’s most abundant minerals and forms the basis of many sandstones and granitic rocks. Milky color results mainly from microscopic fluid inclusions and defects.
Field identification & locations
Field tests include scratching glass with a crystal point and checking that dilute vinegar does not fizz; calcite is softer and reacts with acid. Common worldwide, including Brazil, the United States, Madagascar, and China.