mineral

Milky Quartz

Quartz (Silicon Dioxide - SiO2)

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

Hardness: 7 (Mohs scale)
Color: White to semi-opaque light gray
Luster: Vitreous to greasy

Identified June 20, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to semi-opaque light gray; 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. Milky quartz specifically contains microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, silicon production for electronics, construction aggregate, and occasionally in landscaping or as low-value mineral specimens.

Geological facts

Milky quartz is the most common variety of crystalline quartz on Earth. The milky appearance is caused by millions of tiny bubbles of gas or liquid that were trapped when the crystal was forming.

Field identification & locations

Identify by its hardness (will scratch glass), white milky color, and lack of cleavage. It is found globally in almost all geological environments and commonly occurs as large masses or veins.