mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale. Color: Translucent to white crystals. Luster: Vitreous (glass-like). Crystal Structure: Trigonal. Cleavage: Indistinct. Specific Gravity: 2.65.

Hardness: 7 on Mohs scale
Color: Translucent to white crystals
Luster: Vitreous (glass-like)

Identified July 21, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale. Color: Translucent to white crystals. Luster: Vitreous (glass-like). Crystal Structure: Trigonal. Cleavage: Indistinct. Specific Gravity: 2.65.

Formation & geological history

Geodes form as hollow cavities in volcanic or sedimentary rocks. Over millions of years, mineral-rich water seeps into the hollow and precipitates crystals inward. Most common in desert regions or limestone beds.

Uses & applications

Primarily used for decorative purposes, crystal healing, educational specimens, and lapidary art including jewelry components.

Geological facts

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

Field identification & locations

Identify by a rounded, bumpy exterior that feels lighter than a solid rock of the same size. Commonly found in Iowa (the state rock), Morocco, Brazil, and Mexico. Collectors look for unbroken nodules that sound hollow when tapped.