mineral

Quartz Geode

Crystalline Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: typically white, clear, or off-white; Luster: Vitreous to dull; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 on Mohs scale
Color: typically white, clear, or off-white
Luster: Vitreous to dull

Identified July 1, 2026More mineral →

Explore Quartz Geode 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: typically white, clear, or off-white; Luster: Vitreous to dull; Crystal structure: Trigonal/Hexagonal; Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Formation & geological history

Formed when mineral-rich water seeps into cavities in volcanic or sedimentary rocks. Over millions of years, crystals precipitate and grow inward from the cavity walls.

Uses & applications

Popular in gift stores, home decor, metaphysical practices, and as educational specimens for geology students. Large high-quality vugs are used in high-end interior design.

Geological facts

The word 'geode' comes from the Greek word 'geodes' meaning earth-like. Unlike a nodule which is solid, a geode is hollow and contains crystalline internal structures.

Field identification & locations

Identified in the field by their rounded, lumpy, or potato-like exterior appearance. They often feel lighter than other rocks of the same size due to the hollow interior. Common in desert regions with volcanic history.