mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified February 17, 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: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the cooling of silica-rich magma or from hydrothermal veins. The white color is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth. They can be hundreds of millions of years old.

Uses & applications

Used as a gemstone (cabochons), in glassmaking, as an abrasive, in the electronics industry for its piezoelectric properties, and as decorative landscaping stone.

Geological facts

Milky Quartz is the most common variety of crystalline quartz. While it lacks the transparency of rock crystal, it is chemically identical. It is found on every continent and is a major constituent of granite.

Field identification & locations

Identify in the field by its ability to scratch glass, its distinct white 'cloudy' appearance, and the lack of cleavage planes. Found commonly in mountainous regions, riverbeds, and as veins in metamorphic rocks.