mineral

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

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

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

Identified March 22, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of silica-rich magma or precipitation from hydrothermal veins. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. They are found in all geological ages from Precambrian to recent.

Uses & applications

Used as an abrasive in sandpaper, in glassmaking, and as a source of silicon for semiconductors. In decorative use, it is sold as a healing stone, garden landscaping, or tumbled for jewelry.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It can sometimes be a 'signpost' for gold, as gold is frequently found in quartz veins. Large deposits characterize the 'Mother Lode' in California.

Field identification & locations

Identify in the field by its inability to be scratched by steel, its lack of cleavage (it breaks in curved, shell-like patterns), and its cloudy appearance. Common worldwide in mountain ranges and gravel beds.