mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, milky, or cloudy translucent; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, milky, or cloudy translucent
Luster: Vitreous to greasy

Identified May 24, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, milky, or cloudy translucent; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hydrothermal veins and pegmatites during the late stages of magma cooling or as a product of metamorphic processes. It is one of the most common minerals in the Earth's crust and can be found in rocks from nearly all geological ages.

Uses & applications

Used as a raw material in the manufacture of glass and ceramics, as an abrasive, in electronics for its piezoelectric properties (when high purity), and as decorative stone in landscaping and jewelry.

Geological facts

The milky appearance is caused by tiny inclusions of gas and/or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz found on the surface of the Earth.

Field identification & locations

Identify by its hardness (will scratch glass), lack of cleavage, and white milky appearance. It is found globally in riverbeds, mountains, and near volcanic sites. Collectors look for pieces with internal clarity or unique crystalline habits.