mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: Cloudy white to opaque
Luster: Vitreous to greasy

Identified March 16, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Cloudy white to opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the cooling of silica-rich hydrothermal veins or within igneous pegmatites. The white color is caused by minute fluid inclusions of gas or liquid trapped during crystal growth. They can be found in geological formations ranging from billions of years old to relatively recent.

Uses & applications

Used in the glassmaking and ceramic industries, as a source of silicon for electronics, in landscaping, as a construction aggregate, and occasionally in jewelry as cabochons or beads.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of crystalline quartz. Historically, it was used by various cultures to create stone tools and arrowheads when flint was unavailable.

Field identification & locations

Identify in the field by its ability to scratch glass, its milky white 'cloudy' appearance, and its lack of cleavage planes. It is found globally, common in mountain ranges (Appalachians, Alps, Himalayas) and as common river rocks or gravel.