mineral

Milky Quartz

Crystalline Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: Indistinct; Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Milky white to translucent
Luster: Vitreous to greasy

Identified April 9, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Milky white to translucent; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: Indistinct; Specific gravity: 2.65

Formation & geological history

Forms primarily from hydrothermal solutions in veins or as a late-stage crystallization product in igneous rocks like pegmatites. The white color is caused by microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glassmaking, abrasives, as a flux in metallurgy, and as an ornamental stone in landscaping and jewelry. It is also a source for silicon used in electronics.

Geological facts

Milky quartz is one of the most common mineral varieties on the Earth's crust. Despite its abundance, large, high-clarity specimens are prized by collectors, and it is the state mineral of several regions due to its ubiquity and beauty.

Field identification & locations

Identify in the field by its hardness (scratches glass), white 'cloudy' appearance, and lack of cleavage. It is found globally, often in mountain ranges or as pebbles in riverbeds.