mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

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

Identified May 17, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Opaque white to translucent; 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 rocks like granite. The white color is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, electronics (piezoelectric properties), and as decorative landscaping stone or low-cost collector specimens.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It can often be found in large 'veins' that cut through other rock types, sometimes acting as a host rock for gold.

Field identification & locations

Identified in the field by its distinct white color, lack of cleavage, and ability to scratch glass easily. It is found globally across all continents in mountainous and rocky terrains.