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 23, 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 magma or from hydrothermal veins. The milky appearance is caused by microscopic inclusions of gas and liquid trapped during crystal growth. Can be found in geological formations of almost any age.

Uses & applications

Used as an abrasive, in the production of glass and ceramics, as a source of silicon for electronics, in landscaping, and as decorative stone or low-cost lapidary material.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Historically, it was used to make stone tools and was often associated with 'white stone' lore in various cultures. Milky quartz is the most common variety of quartz.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and white cloudy appearance. It is found globally in igneous, metamorphic, and sedimentary rocks, often appearing as distinct white veins in darker host rock.