mineral

Quartz Geode

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 (Mohs scale); Color: White to transparent crystals inside a brown/tan host rock; Luster: Vitreous (glassy) in crystals; Crystal structure: Hexagonal; Cleavage: None; SG: 2.65

Hardness: 7 (Mohs scale)
Color: White to transparent crystals inside a brown/tan host rock
Luster: Vitreous (glassy) in crystals

Identified May 10, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: White to transparent crystals inside a brown/tan host rock; Luster: Vitreous (glassy) in crystals; Crystal structure: Hexagonal; Cleavage: None; SG: 2.65

Formation & geological history

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

Uses & applications

Primarily used for decorative display, crystal healing, educational purposes, and as collector specimens.

Geological facts

Geodes are often referred to as 'thunder eggs' in certain regions. While they look like ordinary rocks on the outside, their interior can contain hidden crystals untouched for eons.

Field identification & locations

Identify by their round or egg-like shape and unusually light weight compared to solid rocks. Common in desert regions (U.S. Southwest), Brazil, and Mexico.