mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified July 15, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Milky white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; 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 in igneous rocks like granite. The milky appearance is caused by tiny inclusions of liquid or gas trapped during crystal growth.

Uses & applications

Used in glass manufacturing, as an abrasive, in electronics for its piezoelectric properties, as a decorative garden stone, and as a collector specimen.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It is often found associated with gold in hydrothermal veins, leading to it being a primary indicator for surface prospecting during historic gold rushes.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white greasy luster. It is found globally across all geological environments, especially in mountain ranges and riverbeds.