mineral

Milky Quartz

Silicon Dioxide (SiO2)

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

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

Identified March 29, 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 the Mohs scale; Color: Opaque white to translucent; Luster: Vitreous to greasy; Crystal Structure: Trigonal/Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65.

Formation & geological history

Formed from the crystallization of silica-rich hydrothermal fluids or within igneous pegmatites. It is found in geological environments ranging from Precambrian to recent ages, often occurring in veins and large masses.

Uses & applications

Used in glass manufacturing, as an abrasive, in the production of silicon chips for electronics, as landscaping stone, and occasionally in jewelry as cabochons.

Geological facts

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

Field identification & locations

Identify in the field by its white color, ability to scratch glass (hardness 7), and lack of cleavage (it breaks into irregular, sharp curves). Common in mountain ranges and riverbeds globally.