mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, milky, opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, milky, opaque
Luster: Vitreous to greasy

Identified July 5, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, milky, opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins, pegmatites, and igneous rocks through the cooling of silica-rich fluids. It is found in geological formations ranging from Precambrian to Cenozoic eras.

Uses & applications

Used in glass making, ceramics, as an abrasive, in the semiconductor industry (silicon source), and as landscape stone or ornamental specimens.

Geological facts

Milky quartz gets its white color from microscopic fluid inclusions of gas or liquid trapped during crystal growth. It is the most common variety of crystalline quartz on Earth.

Field identification & locations

Identify by its hardness (scratches glass), white color, and lack of cleavage. Often found as rounded pebbles in stream beds or as massive veins in outcrops.