mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Opaque white to light gray, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65

Identified July 18, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Opaque white to light gray, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and pegmatites through the cooling of silica-rich fluids. It is found in igneous, metamorphic, and sedimentary environments worldwide across many geological ages.

Uses & applications

Used in glass making, as an abrasive, in electronics (though synthetic is preferred), for construction aggregate, and as a decorative stone in landscaping or jewelry.

Geological facts

The milky appearance is caused by tiny inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz.

Field identification & locations

Identify in the field by its hardness (scratches glass), white color, and lack of cleavage. It is extremely common in gravel beds and mountain outcrops.