mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: Opaque white to cream with slight brownish iron staining; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: Opaque white to cream with slight brownish iron staining
Luster: Vitreous to greasy

Identified June 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins or as a late-stage crystallization in igneous pegmatites. It gets its milky appearance from numerous microscopic inclusions of gas and liquid trapped during crystal growth.

Uses & applications

Used in glass manufacturing, as an abrasive, in the production of silicon chips, and as landscape gravel. Dense varieties are sometimes carved for ornamental jewelry.

Geological facts

Milky quartz is the most common variety of crystalline quartz. The white color is actually caused by millions of tiny bubbles of gas or fluid trapped inside the crystal as it formed.

Field identification & locations

Identified by its high hardness (scratches glass), lack of cleavage, and white opaque appearance. It is found worldwide, very commonly in mountainous regions or inside riverbeds.