mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified June 27, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The white color is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, semiconductor industry (silicon source), and as landscaping stone. Low-grade specimens are common for decorative gravel.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It is responsible for the white veins often seen cutting through darker host rocks in mountain ranges.

Field identification & locations

Identify in the field by its hardness (will scratch glass), white color, and lack of cleavage. Found globally in almost all geological environments, especially in riverbeds and mountainous terrain.