mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Identified April 25, 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 waxy white, Luster: Vitreous to greasy, Crystal structure: Trigonal/Hexagonal, Cleavage: None (Conchoidal fracture), Specific Gravity: 2.65

Formation & geological history

Formed from silica-rich hydrothermal fluids cooling in igneous veins or pegmatites; milky appearance is caused by tiny fluid inclusions trapped during crystal growth. Can be found in rocks of various geological ages.

Uses & applications

Used in electronics as a source of high-purity silica, as landscaping stone, in glass manufacturing, and as decorative garden boulders.

Geological facts

Milky quartz is the most common variety of crystalline quartz. Historically, it was sometimes used by prehistoric cultures for toolmaking when finer materials like flint were unavailable.

Field identification & locations

Identify in the field by its distinct white color, inability to be scratched by steel, and lack of cleavage planes. Found globally in mountainous regions and riverbeds.