sedimentary

Quartz Geode (Unbroken)

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale); Color: White, tan, or gray exterior; Luster: Dull/earthy exterior, vitreous (glassy) interior; Crystal Structure: Hexagonal; Specific Gravity: 2.65

Hardness: 7 (Mohs scale)
Color: White, tan, or gray exterior
Luster: Dull/earthy exterior, vitreous (glassy) interior

Identified June 2, 2026More sedimentary →

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Physical properties

Hardness: 7 (Mohs scale); Color: White, tan, or gray exterior; Luster: Dull/earthy exterior, vitreous (glassy) interior; Crystal Structure: Hexagonal; Specific Gravity: 2.65

Formation & geological history

Formed in sedimentary rocks like limestone or volcanic rocks where mineral-rich water seeps into cavities, slowly depositing layers of crystals. Often found in strata from the Carboniferous to Jurassic periods.

Uses & applications

Collecting, decorative ornaments, education, and metaphysical use.

Geological facts

The word geode comes from the Greek word 'Geoides' which means 'earth-like'. Despite looking like an ordinary rock on the outside, they contain hollow cavities lined with crystals.

Field identification & locations

Identify by its round or egg-like shape and unusually light weight compared to solid rocks of the same size. Commonly found in desert regions of the US states like Iowa, Indiana, and Kentucky.