mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 (Mohs scale), Color: Clear/White/Off-white, Luster: Vitreous to greasy, Crystal structure: Hexagonal (Trigonal), Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Identified May 31, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale), Color: Clear/White/Off-white, Luster: Vitreous to greasy, Crystal structure: Hexagonal (Trigonal), Cleavage: None/Conchoidal fracture, Specific gravity: 2.65

Formation & geological history

Formed in hollow cavities of sedimentary or volcanic rocks. Mineral-rich groundwater precipitates crystals over thousands to millions of years. This specimen likely formed in an arid or volcanic environment.

Uses & applications

Primary use as ornamental display pieces, home decor, holistic/energy healing use, and as affordable entry-level items for mineral collectors.

Geological facts

Geodes are often referred to as 'thunder eggs' when they are filled with solid agate. No two geodes are exactly alike inside, and their exterior often looks like an ordinary, lumpy rock before being cracked open.

Field identification & locations

Identify in the field by looking for rounded, knobby stones that feel unusually lightweight for their size (indicating a hollow center). Common in areas with limestone or volcanic basalt deposits.