mineral

Quartz Geode

Crystalline Silicon Dioxide (SiO2)

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

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

Identified July 5, 2026More mineral →

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Physical properties

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

Formation & geological history

Formed when mineral-rich water enters hollow cavities in sedimentary or volcanic rock, depositing layers of silica over thousands of years to create inward-growing crystals.

Uses & applications

Primarily used for decorative display, crystal collecting, metaphysical purposes, and jewelry. Industrial clear quartz is used in oscillators and glass manufacturing.

Geological facts

A geode is basically a rock that is hollow on the inside with crystal linings; the name comes from the Greek word 'Geoides' meaning 'earth-like'. No two geodes are exactly alike.

Field identification & locations

Identify in the field by looking for rounded, bumpy, lightweight nodules. Common locations include Brazil, Mexico, and the United States (notably Iowa and Utah). Collectors look for unbroken stones that feel lighter than expected for their size.