mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, milky, or gray; Luster: Vitreous to greasy; Crystal structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, milky, or gray
Luster: Vitreous to greasy

Identified July 8, 2026More mineral →

Explore Milky Quartz in the encyclopedia →

Identify your own rocks.

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

App Store Google Play

Physical properties

Hardness: 7 (Mohs scale); Color: White, milky, or gray; Luster: Vitreous to greasy; Crystal structure: Hexagonal (trigonal); Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Forms in hydrothermal veins or pegmatites where silica-rich fluids cool slowly; often found in all types of environments including igneous, metamorphic, and sedimentary rocks.

Uses & applications

Used as a landscape stone, in glass making, as a source of silicon for electronics, and occasionally for carving or low-value jewelry.

Geological facts

Milky quartz gets its white color from tiny bubbles of gas or liquid trapped during its formation. It is the most common variety of crystalline quartz.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), lack of cleavage, and white opaque color. It is commonly found in mountainous regions or as pebbles in riverbeds.