mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Milky white to tan/brown due to iron staining; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct (conchoidal fracture).

Hardness: 7 on Mohs scale
Color: Milky white to tan/brown due to iron staining
Luster: Vitreous to greasy

Identified July 17, 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 on Mohs scale; Color: Milky white to tan/brown due to iron staining; Luster: Vitreous to greasy; Crystal Structure: Hexagonal (trigonal); Cleavage: Indistinct (conchoidal fracture).

Formation & geological history

Forms during the final stages of magmatic crystallization in hydrothermal veins or pegmatites. It is often found in large, opaque masses containing microscopic inclusions of gas or liquid.

Uses & applications

Used in glass making, abrasives, electronics (as a source of silicon), and as decorative landscaping stone or collectibles.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. The 'milky' appearance is caused by tiny bubbles of gas or liquid trapped during the crystal's growth.

Field identification & locations

Identifiable by its inability to be scratched by a steel knife and its lack of cleavage. Commonly found in mountain ranges, riverbeds, and as veins in other rock types worldwide.