mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified May 9, 2026More mineral →

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Physical properties

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

Formation & geological history

Forms from the cooling of silica-rich magma or through hydrothermal activity in veins within igneous, sedimentary, and metamorphic rocks. The milky color is caused by tiny inclusions of liquid, gas, or both, trapped during crystal growth.

Uses & applications

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

Geological facts

Milky quartz is the most common variety of crystalline quartz. It is often found as the 'matrix' for other minerals like gold in hydrothermal veins.

Field identification & locations

Identify by its ability to scratch glass, its lack of cleavage (it breaks into irregular, sharp fragments), and its opaque white color. It is ubiquitous worldwide, especially in mountain ranges and streambeds.