sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to white crystals; Luster: Vitreous/glassy; Crystal Structure: Hexagonal crystals; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Hardness: 7 on Mohs scale
Color: Clear to white crystals
Luster: Vitreous/glassy

Identified May 22, 2026More sedimentary →

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: Clear to white crystals; Luster: Vitreous/glassy; Crystal Structure: Hexagonal crystals; Cleavage: None (conchoidal fracture); Specific gravity: 2.65

Formation & geological history

Formed in hollow cavities of sedimentary rocks through the precipitation of minerals from hydrothermal fluids or groundwater over thousands to millions of years.

Uses & applications

Primarily used as decorative specimens, for educational purposes, in jewelry (when sliced), and by crystal collectors for aesthetic value.

Geological facts

The word 'geode' comes from the Greek word 'geodes', meaning earth-like. They look like ordinary round stones from the outside but contain hollow, crystal-lined interiors.

Field identification & locations

Identify by their rounded shape and lightness compared to solid rocks of the same size. A hollow sound when tapped can indicate a geode. Commonly found in deserts or limestone-rich areas.