mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous/glassy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White to translucent
Luster: Vitreous/glassy

Identified June 22, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: White to translucent; Luster: Vitreous/glassy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal solutions or cooling magma in veins and pegmatites. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, semiconductor manufacturing, and as decorative gravel or low-cost gemstones in jewelry.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is common because the 'milkiness' is caused by tiny bubbles of fluids trapped when the crystal was forming millions of years ago.

Field identification & locations

Identify in the field by its hardness (will scratch glass), white milky color, and lack of cleavage (it breaks in irregular, shell-like curves). It is found globally across all continents in mountainous and rocky terrains.