mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Cloudy white to grayish
Luster: Vitreous (glassy) to greasy

Identified March 9, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or as a late-stage mineral in igneous pegmatites. It is found in geological environments ranging from Precambrian to recent ages.

Uses & applications

Used in the glass and ceramic industries, as an abrasive in sandpaper, in the production of silicon metal for electronics, and as decorative gravel or crushed stone in construction. Higher quality specimens are used for lapidary work and carvings.

Geological facts

Milky quartz gets its characteristic white, 'cloudy' appearance from tiny fluid inclusions (bubbles of gas or liquid) trapped during the crystal's growth. It is the most common variety of crystalline quartz found on Earth.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), its white opaque color, and its lack of cleavage (it breaks into curved, shell-like fragments). It is ubiquitous globally, often found as 'river rocks' or vein outcroppings in mountain ranges.