mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified April 19, 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 opaque; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed through the crystallization of magma or from hydrothermal veins. The milky appearance is caused by tiny fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in jewelry as cabochons or beads, as a source of silica for glassmaking, in electronics (due to piezoelectricity), and as decorative landscaping stone.

Geological facts

Milky quartz is the most common variety of crystalline quartz. While often overlooked for clearer varieties, it can contain microscopic inclusions of gold or other valuable minerals in specific geological veins.

Field identification & locations

Identify in the field by its white color, ability to scratch glass (hardness 7), and lack of cleavage. Commonly found in riverbeds, pegmatites, and mountain ranges globally. Beginners often find these as 'river pebbles'.