mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified May 25, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent of igneous rocks. The 'milky' appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used as a source of silicon for semiconductors, in ceramics, as an abrasive, and frequently as a decorative landscaping stone or tumbled pocket stone for collectors.

Geological facts

Milky quartz is the most common variety of crystalline quartz on Earth. The milky color is due to microscopic fluid inclusions that occurred during the crystal's formation over millions of years.

Field identification & locations

Identify by its white 'cloudy' color and ability to scratch glass. Commonly found in gold-bearing quartz veins and pegmatites worldwide. Collectors often find them in stream beds as water-worn pebbles.