mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Mohs hardness of 7, vitreous to greasy luster, trigonal crystal system, conchoidal fracture, white to yellowish-cream color due to microscopic fluid inclusions and iron oxide staining.

Identified July 24, 2026More mineral →

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Physical properties

Mohs hardness of 7, vitreous to greasy luster, trigonal crystal system, conchoidal fracture, white to yellowish-cream color due to microscopic fluid inclusions and iron oxide staining.

Formation & geological history

Forms in a wide variety of geological environments, most commonly in pegmatites, hydrothermal veins, and metamorphic rocks. Milky appearance is caused by tiny bubbles of gas and liquid trapped during crystal growth.

Uses & applications

Used as an abrasive, in glassmaking, electronics (piezoelectric properties), gemstone carvings, decorative stones, and as educational/collector specimens.

Geological facts

Milky Quartz is one of the most common mineral varieties on Earth. The milky, opaque appearance is due to millions of microscopic fluid inclusions trapped during the mineral's rapid growth millions of years ago.

Field identification & locations

Identified by its scratch-hardness (scratches glass easily, cannot be scratched by steel), lack of cleavage, milky white to yellowish hue, and greasy to vitreous luster. Extremely common worldwide in gravel deposits, mountain veins, and creek beds.