mineral

Milky Quartz

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: White, cloudy, or translucent milky; Luster: Vitreous to greasy; Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Hardness: 7 on Mohs scale
Color: White, cloudy, or translucent milky
Luster: Vitreous to greasy

Identified May 18, 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: White, cloudy, or translucent milky; Luster: Vitreous to greasy; Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed through the crystallization of silica-rich hydrothermal fluids in veins or as a primary constituent in igneous rocks like granite. The milky appearance is caused by tiny inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in the production of glass, ceramics, and abrasives. High-purity quartz is used in electronics and semiconductors. While common, attractive pieces are used as decorative garden stones or for lapidary work.

Geological facts

Milky quartz is the most common variety of crystalline quartz. It is often the primary gangue mineral in gold-bearing hydrothermal veins, making it a key indicator for prospectors.

Field identification & locations

Identify by its hardness (will scratch glass), lack of cleavage, and characteristic waxy or milky white appearance. It is found globally in mountainous regions, pegmatites, and stream beds.