mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Cloudy white to opaque
Luster: Vitreous (glassy) to greasy

Identified March 26, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

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

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids in veins or from cooling magma in igneous rocks. The milky appearance is caused by microscopic inclusions of fluids or gas trapped during crystal growth. Can be found in geological formations ranging from Precambrian to Cenozoic eras.

Uses & applications

Used as an abrasive, in the production of glass and ceramics, as an additive in concrete, and widely as a decorative stone or 'tumbled stone' for collectors and metaphysical uses.

Geological facts

Milky Quartz is the most common variety of crystalline quartz. While most quartz is clear, the white cloudiness acts as a 'geological time capsule' by trapping ancient liquids and gases within the mineral structure.

Field identification & locations

Identify in the field by its distinct white color, inability to be scratched by a steel knife (hardness of 7), and lack of cleavage. It is found globally, particularly in pegmatites and mountain ranges like the Appalachians or Alps.