mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 Mohs; Color: Colorless to white crystals with a tan/brown host rock; Luster: Vitreous (glassy) crystals; Structure: Hexagonal crystal system (trigonal); Cleavage: None/Conchoidal fracture.

Hardness: 7 Mohs
Color: Colorless to white crystals with a tan/brown host rock
Luster: Vitreous (glassy) crystals

Identified July 20, 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

Formation & geological history

Formed as hollow nodules in sedimentary or volcanic rocks. Mineral-rich groundwater seeps into gas bubbles or cavities over millions of years, precipitating layers of quartz crystals toward the center.

Uses & applications

Primarily used as decorative display specimens, educational tools, and in metaphysical rock collecting.

Geological facts

The word geode comes from the Greek word 'Geoides' meaning earth-like. Unlike a vug, a geode is a separate entity from the surrounding rock and can be removed as a whole nodule.

Field identification & locations

Identified by a lumpy, spherical exterior that feels lighter than a solid rock of the same size. To find them in the field, look for round, cauliflower-like rocks in streambeds or limestone/shale outcrops.