mineral

Quartz Geode

Silicon Dioxide (SiO2)

AI-generated identification · may be incorrect

Hardness: 7 Mohs; Color: White/Clear; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal prisms inside cavity); Cleavage: None; Specific Gravity: 2.65

Hardness: 7 Mohs
Color: White/Clear
Luster: Vitreous to greasy

Identified July 9, 2026More mineral →

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Physical properties

Hardness: 7 Mohs; Color: White/Clear; Luster: Vitreous to greasy; Crystal Structure: Trigonal (hexagonal prisms inside cavity); Cleavage: None; Specific Gravity: 2.65

Formation & geological history

Formed as secondary structures in sedimentary or volcanic rocks. Mineral-rich waters seep into cavities (gas bubbles or fossil openings), precipitating quartz crystals over thousands of years.

Uses & applications

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

Geological facts

The word geode comes from the Greek word 'geodes' meaning earth-like. No two geodes are exactly alike inside, making each a unique natural time capsule.

Field identification & locations

Identify by looking for rounded, cauliflower-like exterior nodules that feel lighter than solid rocks. Common in Morocco, Brazil, and the US Midwest (Iowa, Indiana).