mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Opaque white to translucent white. Luster: Vitreous (glassy) to greasy. Crystal structure: Trigonal/Hexagonal. Cleavage: None (conchoidal fracture). Specific gravity: 2.65.

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

Identified February 12, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or through hydrothermal activity in veins. The white color is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. Can be found in geological environments ranging from Precambrian to Holocene.

Uses & applications

Used as a gemstone (cabochons), in landscaping, as an abrasive, and as a source of silicon for integrated circuits and glass manufacturing. Often collected as decorative 'yard rock'.

Geological facts

Milky Quartz is the most common variety of crystalline quartz. While it lacks the clarity of rock crystal, the trapped bubbles that give it its color can provide a ‘frozen in time’ look at the chemical composition of the fluids present during its formation.

Field identification & locations

Identify by its 'cloudy' appearance and high hardness (it will scratch glass). Commonly found in pegmatites and metamorphic belts globally. Collectors look for large, well-formed hexagonal points.