mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White to milky translucent, Luster: Vitreous to greasy, Crystal Structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified July 21, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: White to milky translucent, Luster: Vitreous to greasy, Crystal Structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent of igneous rocks like granite. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glass manufacturing, as an abrasive, in electronics for its piezoelectric properties (high purity), and as a landscaping stone or collector specimen.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It is often found associated with gold in hydrothermal vein deposits, making it a key indicator for prospectors.

Field identification & locations

Look for a white, hard mineral that can scratch glass and does not react with acid. It often occurs as massive chunks or prismatic crystals in mountain ranges and gravel beds.