mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: White to cloudy
Luster: Vitreous to greasy

Identified June 18, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed in hydrothermal veins through the precipitation of silica-rich fluids in rock fractures. Common in pegmatites and metamorphic environments. Can be found in geological formations of almost any age across the globe.

Uses & applications

Used as a source of silicon for semiconductors and glassmaking. Also used in abrasives, construction aggregates, and occasionally as a base material for carving or as a decorative landscaping stone.

Geological facts

Milkiness is caused by tiny inclusions of gas or liquid trapped during the crystal's growth. It is the most common variety of crystalline quartz.

Field identification & locations

Identify by its white, opaque appearance and inability to be scratched by a steel knife. Commonly found in riverbeds, quartz veins, and mountain ranges. Collectors look for unique inclusions or crystalline facets.