mineral

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

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

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

Identified May 9, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins or pegmatites when silica-rich fluids cool. The milky appearance is caused by tiny inclusions of gas and liquid trapped during crystal growth. Can be found in almost all geological environments and ages.

Uses & applications

Used as an abrasive, in the production of glass and ceramics, as a flux in metallurgy, in landscaping, and occasionally as a semi-precious gemstone or for metaphysical collecting.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it has been used as a tool stone for making arrowheads and scrapers when chert was unavailable.

Field identification & locations

Identify by its white 'milk' color, inability to be scratched by a steel knife, and lacks cleavage. Commonly found in gravel pits, riverbeds, and as veins in metamorphic or igneous outcrops.