mineral

Quartz Geode

Crystalline Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: Clear to white internal crystals with a grey/brown outer rind; Luster: Vitreous (glassy) crystals; Crystal Structure: Hexagonal/Trigonal; Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Luster: Vitreous (glassy) crystals

Identified May 30, 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: Clear to white internal crystals with a grey/brown outer rind; Luster: Vitreous (glassy) crystals; Crystal Structure: Hexagonal/Trigonal; Specific Gravity: 2.65.

Formation & geological history

Formed in hollow cavities of volcanic or sedimentary rocks where mineral-rich groundwater precipitates crystals over thousands to millions of years. This piece specifically appears to be a quartz-filled volcanic geode.

Uses & applications

Primarily used for home decor, educational displays, meditation/metaphysical practices, and as a popular specimen for mineral collectors.

Geological facts

Geodes are like time capsules; the air inside a sealed geode can be millions of years old. The term 'geode' comes from the Greek word 'Geoides' meaning 'earth-like'.

Field identification & locations

Identified by a round or egg-shaped exterior with a bumpy 'cauliflower' texture that feels lighter than a solid rock of the same size. Commonly found in deserts or volcanic ash beds in locations like Brazil, Morocco, and the Midwestern US.