mineral

Quartz Geode

Crystalline Silicon Dioxide (SiO2) in a Geode

Hardness: 7 (Mohs scale); Color: Clear to white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Hardness: 7 (Mohs scale)
Color: Clear to white
Luster: Vitreous (glassy)

Identified June 17, 2026More mineral →

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Physical properties

Hardness: 7 (Mohs scale); Color: Clear to white; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (Trigonal); Cleavage: None/Conchoidal fracture; Specific gravity: 2.65.

Formation & geological history

Formed via the precipitation of minerals from hydrothermal fluids or groundwater within hollow cavities in sedimentary or volcanic rocks. The outer shell is often chalcedony or limestone. These can range from millions to hundreds of millions of years old.

Uses & applications

Primarily used for decorative display, educational purposes, healing crystal practices, and as collectibles. Large, high-quality geodes can be used in interior design.

Geological facts

The word geode comes from the Greek word 'Geoides' which means earth-like. No two geodes are exactly alike on the inside, even if they look identical on the outside.

Field identification & locations

Identify in the field by looking for rounded, bumpy, potato-like rocks that feel lighter than they look. Found globally, with famous deposits in Morocco, Brazil, and the Midwestern United States (Keokuk geodes).

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