mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Cloudy white to grayish
Luster: Vitreous to greasy

Identified June 10, 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 grayish; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Forms in hydrothermal veins and pegmatites through the cooling of silica-rich solutions. It is found in many geological environments and ages, ranging from Precambrian to recent formations.

Uses & applications

Used in glass making, as an abrasive, in the production of silicon alloys, as a landscaping material, and as a collector's specimen.

Geological facts

Milky quartz gets its cloudy appearance from minute fluid inclusions of gas or liquid trapped during crystal growth. It is the most common variety of crystalline quartz.

Field identification & locations

Identify by its hardness (scratches glass), lack of cleavage, and white cloudy appearance. Common in gravel beds and mountain trails worldwide. Collectors should look for well-defined crystal faces.