mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to translucent with yellow/brown iron staining; Luster: Vitreous to greasy; Crystal structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Milky white to translucent with yellow/brown iron staining
Luster: Vitreous to greasy

Identified June 25, 2026More mineral →

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Physical properties

Formation & geological history

Forms in hydrothermal veins or as a constituent of igneous rocks like granite. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth. Can be found in geological formations of any age from Precambrian to Cenozoic.

Uses & applications

Used in construction as aggregate, in glass manufacturing, as an abrasive, in electronics for its piezoelectric properties, and as decorative gravel or tumbled stones for collectors.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of quartz. Its white color is often due to light scattering by microscopic fluid inclusions.

Field identification & locations

Identify in the field by its hardness (scratches glass), lack of cleavage, and characteristic waxy/glassy luster. It often survives erosion better than surrounding minerals, leading to the formation of white river pebbles.