mineral

Quartz / Milky Quartz

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Cloudy white to translucent
Luster: Vitreous (glassy)

Identified March 22, 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 translucent; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from the cooling of silica-rich magma or through hydrothermal precipitation in veins. Found in various geological ages and environments, common in pegmatites and metamorphic rocks.

Uses & applications

Broadly used in glass manufacturing, electronics (due to piezoelectric properties), abrasives, construction aggregates, and as gemstones or collector specimens.

Geological facts

Quartz is the second most abundant mineral in Earth's continental crust. Its name comes from the German word 'Quarz' and the Polish term for 'hard'. Some of the oldest known quartz crystals are billions of years old.

Field identification & locations

Identify in the field by its ability to scratch glass and lack of cleavage (it breaks in irregular, shell-like curves). It is found globally, particularly in mountainous regions and riverbeds.