mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: Opaque white to translucent; Luster: Vitreous (glassy) to waxy when tumbled; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Opaque white to translucent
Luster: Vitreous (glassy) to waxy when tumbled

Identified February 19, 2026More mineral →

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Physical properties

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or cooling magma. The milky appearance is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth. Can be found in rocks of any geological age.

Uses & applications

Used in the glass and ceramics industry, as a source of silicon for semi-conductors, as an abrasive, in landscaping/construction, and commonly as tumbled pocket stones or decorative carvings in the crystal collecting community.

Geological facts

Milky quartz is the most common variety of crystalline quartz on Earth. The 'milkiness' is actually a structural defect where tiny bubbles of high-pressure water and gas are trapped inside since the moment of its formation millions of years ago.

Field identification & locations

Identify in the field by its ability to scratch glass, its lack of cleavage, and its distinctive white, cloudy appearance. It is ubiquitous globally, commonly found in mountain ranges, stream beds, and gravel pits. Collectors look for pieces with interesting inclusions or unique water-worn shapes.