mineral

Quartz (Milky/Clear variety)

Silicon Dioxide (SiO2)

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

Hardness: 7 on Mohs scale
Color: Translucent to milky white
Luster: Vitreous (glassy)

Identified April 7, 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: Translucent to milky white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed from the cooling of magma or by hydrothermal precipitation in veins. Quartz is common throughout all geological periods and is found in igneous, metamorphic, and sedimentary environments.

Uses & applications

Used in electronics (as piezoelectric crystals), glass manufacturing, abrasives, jewelry, and as a popular specimen for collectors.

Geological facts

Quartz is one of the most abundant minerals in Earth's crust. It is highly resistant to both chemical and physical weathering, which is why it often remains as river pebbles or sand.

Field identification & locations

Identify by its ability to scratch glass or steel, its glassy luster, and the lack of cleavage (it breaks in curved surfaces). Common in granite outcroppings and river beds worldwide.