mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified June 8, 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 milky; Luster: Vitreous to greasy; Crystal Structure: Trigonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed primarily in hydrothermal veins and pegmatites through the cooling of silica-rich hot water or magma; can be found in rocks of almost any geological age.

Uses & applications

Used in glassmaking, as an abrasive, in the production of silicon chips, as a component in concrete, and frequently as decorative gravel or landscaping stone.

Geological facts

The milky appearance is caused by tiny bubbles of gas or liquid trapped during the crystal's formation. It is the most common variety of crystalline quartz found on Earth's crust.

Field identification & locations

Identify by its white opaque color, inability to be scratched by steel, and distinct conchoidal (shell-like) fracture. Commonly found in riverbeds, mountains, and near mining sites worldwide.