mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Identified May 17, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent in igneous and metamorphic rocks. Its white color is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glass making, abrasive blasting, electronics (piezoelectric properties), and commonly as a decorative stone in landscaping or as a semi-precious collector specimen.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It can often contain trace amounts of gold in hydrothermal veins, which is why prospectors look for white quartz 'reefs'.

Field identification & locations

Identify by its hardness (will scratch glass), lack of cleavage, and white cloudy appearance. It is found globally and is highly abundant in mountain ranges and riverheds.