mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: White to translucent gray, Luster: Vitreous to greasy, Crystal Structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Identified June 26, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 7 (Mohs scale), Color: White to translucent gray, Luster: Vitreous to greasy, Crystal Structure: Hexagonal (trigonal), Cleavage: None (conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins, pegmatites, and as a primary constituent in igneous rocks like granite. It crystallizes from silica-rich fluids deep within the Earth's crust across all geological ages.

Uses & applications

Used in glass manufacturing, electronics (piezoelectric properties), abrasives, construction aggregates, and as decorative gravel or low-cost gemstones in jewelry.

Geological facts

Milky quartz gets its cloudy appearance from microscopic inclusions of gas or liquid trapped during crystal growth. It is one of the most abundant minerals on the Earth's surface.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), various shades of white, and lack of cleavage. It is commonly found in riverbeds, mountain ranges, and quartz veins within host rocks.