mineral

Quartz Geode Fragment

Silicon Dioxide (SiO2)

Hardness: 7 on Mohs scale; Color: colorless to white (milky) crystals; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

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

Identified May 8, 2026More mineral →

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Physical properties

Hardness: 7 on Mohs scale; Color: colorless to white (milky) crystals; Luster: Vitreous (glassy); Crystal Structure: Hexagonal; Cleavage: None (conchoidal fracture); Specific Gravity: 2.65

Formation & geological history

Formed as secondary mineral precipitates in hollow cavities (vugs) within igneous or sedimentary rocks. Hydrothermal fluids rich in silica deposit layers of crystals over thousands of years.

Uses & applications

Used in gemstone and jewelry production, crystal healing, collection, and industrial electronics as a piezoelectric material.

Geological facts

Geodes appear as ordinary mud-covered rocks from the outside, but contain beautiful crystalline voids inside. The word geode comes from the Greek word Geoides, which means earth-like.

Field identification & locations

Identify by the rough, brownish exterior rind contrasting with the white, sparkling internal crystalline structure. Common in desert regions such as Utah or volcanic regions like Brazil.