mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Formation & geological history

Forms 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 microscopic fluid inclusions of gas or liquid trapped during crystal growth.

Uses & applications

Used in glass making, ceramics, as an abrasive, in the electronics industry for its piezoelectric properties (when clear), and as a landscaping stone or collector specimen.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz specifically is one of the most common varieties found worldwide and often contains traces of gold in hydrothermal vein deposits.

Field identification & locations

Identify in the field by its hardness (will scratch glass), lack of cleavage, and white 'milky' opacity. Commonly found in riverbeds, mountain ranges, and near granite outcrops.