mineral

Quartz (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 20, 2026More mineral →

Explore Quartz (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

Formed via hydrothermal activity where silica-rich fluids crystallize in veins, or as a primary constituent in igneous rocks like granite. The milky appearance is caused by microscopic fluid inclusions trapped during crystal growth.

Uses & applications

Used in glass making, abrasive manufacturing, electronics (due to piezoelectric properties), and as a gemstone or decorative specimen.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Milky quartz is the most common variety of crystalline quartz found in nature.

Field identification & locations

Identified in the field by its hardness (it can scratch glass and steel), lack of cleavage, and white streak. It is ubiquitous in mountainous regions and riverbeds worldwide.