mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Opaque white to translucent; Luster: Vitreous (glassy) to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct/Conchoidal fracture; Specific Gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Opaque white to translucent
Luster: Vitreous (glassy) to greasy

Identified July 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed from the cooling of silica-rich hydrothermal fluids or within igneous pegmatites. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Common in Precambrian metamorphic and igneous terrains.

Uses & applications

Used as a source of silicon in electronics, as an abrasive, in glassmaking, construction aggregate, and as a semi-precious stone in jewelry and carvings.

Geological facts

Quartz is one of the most abundant minerals in Earth's crust. The milky variety is essentially rock crystal that contains microscopic 'bubbles,' which scatter light to create the white color.

Field identification & locations

Identify by its ability to scratch glass and its lack of cleavage (it breaks in curved, shell-like patterns). Found globally; the Luanda province of Angola (near 8.8°S, 13.4°E) features sedimentary basins and metamorphic outcrops where quartz veins are very common.