mineral

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: White to translucent
Luster: Vitreous to greasy

Identified June 19, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins or pegmatites from late-stage crystallization of silica-rich magma or hot geothermal fluids. Can be found in almost all geological ages.

Uses & applications

Used in glass making, as an abrasive, in the semiconductor industry (silicon source), as landscape stones, and occasionally in jewelry as cabochons.

Geological facts

The 'milky' appearance is caused by tiny inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz.

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and white greasy appearance. Highly abundant worldwide, particularly in mountains and riverbeds.