Milky Quartz

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 white color is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth. Can be found in geological environments ranging from Precambrian to recent ages.

Uses & Applications

Used in glass manufacturing, as an abrasive, in the production of silicon chips, and as decorative stone in landscaping. Lower quality milky quartz is primarily used as industrial aggregate.

Geological Facts

Milky quartz is the most common variety of crystalline quartz. It can sometimes contain small amounts of gold within its veins, making it a target for prospectors. The 'milkiness' is due to millions of tiny gas and liquid bubbles.

Field Identification & Locations

Identify by its ability to scratch glass, lack of cleavage, and white cloudy appearance. Common worldwide in granitic rocks and pegmatites. Collectors look for pieces with interesting surface textures or associations with other minerals.

Identified on: 4/23/2026

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