mineral

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale (scratches glass); Color: White, translucent to opaque; Luster: Vitreous (glassy) to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale (scratches glass)
Color: White, translucent to opaque
Luster: Vitreous (glassy) to greasy

Identified March 24, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the cooling of magma or by hydrothermal activity where silica-rich fluids precipitate into veins and cavities. The white 'milky' appearance is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Extensively used in construction as aggregate, in glass manufacturing, as an abrasive, in the production of silicon for electronics, and as a low-cost lapidary material for landscaping and aquarium decor.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of crystalline quartz. Historically, it has been used for stone tools since the Paleolithic period due to its predictable fracture patterns.

Field identification & locations

Identify in the field by its distinct white color, inability to be scratched by a steel knife, and lacks cleavage (it breaks into irregular, glass-like curved shards). Commonly found in mountain ranges, riverbeds, and as quartz veins in granitic or metamorphic environments.