sedimentary

Quartz Geode

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale); Color: White, gray, or clear crystals; Luster: Vitreous to waxy; Crystal structure: Hexagonal (trigonal); Cleavage: None; Specific gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, gray, or clear crystals
Luster: Vitreous to waxy

Identified July 5, 2026More sedimentary →

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 (Mohs scale); Color: White, gray, or clear crystals; Luster: Vitreous to waxy; Crystal structure: Hexagonal (trigonal); Cleavage: None; Specific gravity: 2.65

Formation & geological history

Formed as hollow cavities in sedimentary or volcanic rock that are filled by the slow precipitation of mineral-rich water over millions of years.

Uses & applications

Primarily used for decorative purposes, collecting, educational specimens, and metaphysical uses.

Geological facts

The word geode comes from the Greek word 'Geoides' meaning earth-like. Unlike a vug, which is a cavity in a rock vein, a geode is a separate, rounded structure that can be removed from the host rock intact.

Field identification & locations

Identify by its rounded exterior and hollow interior lined with crystals. Common in limestone deposits such as the Keokuk region of the Midwestern USA, or volcanic regions in Brazil and Mexico.