mineral

Milky quartz

Quartz, silicon dioxide (SiO₂)

AI-generated identification · may be incorrect

Typically white to translucent with a vitreous-to-waxy luster, irregular fracture, and no cleavage; Mohs hardness 7, trigonal crystal structure, and specific gravity about 2.65. The specimen appears massive and uncrystallized, with possible surface weathering or iron staining.

Identified August 9, 2026More mineral →

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Physical properties

Formation & geological history

Forms when silica-rich fluids crystallize in veins, cavities, and igneous or metamorphic rocks; milky appearance results from microscopic fluid inclusions and fractures. Quartz is common throughout geological time, from Precambrian rocks to modern hydrothermal deposits.

Uses & applications

Used in glassmaking, ceramics, abrasives, electronics, engineered stone, and as a collector specimen; attractive transparent varieties are used as gemstones.

Geological facts

Commonly confused with calcite, but quartz is harder and does not effervesce in dilute hydrochloric acid. Field tests include scratching glass and checking for the absence of cleavage.

Field identification & locations

Found worldwide, especially in quartz veins, pegmatites, granites, and metamorphic rocks. This rough, common specimen has an estimated value of $1–$10; larger aesthetic pieces may bring $10–$30.