mineral

Quartz Geode

Silicon Dioxide (SiO2) within a geode

Hardness: 7 on Mohs scale; Color: Clear to white crystals; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

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

Identified June 2, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: Clear to white crystals; Luster: Vitreous (glassy); Crystal Structure: Hexagonal (trigonal); Cleavage: None/Conchoidal fracture; Specific Gravity: 2.65

Formation & geological history

Formed in hollow cavities of sedimentary or volcanic rocks where mineral-rich groundwater deposits silica over long periods, often millions of years, allowing crystals to grow inward.

Uses & applications

Primarily used as decorative display pieces, for geological education, in crystal healing practices, and as collector specimens.

Geological facts

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

Field identification & locations

Identify in the field by looking for round, lumpy rocks that feel lighter than expected for their size (indicating hollow space). Commonly found in desert regions of Morocco, Mexico, and the Midwestern United States.