mineral

Quartz Geode

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, typically white, clear, or grey in color, vitreous to sugary luster, trigonal crystal system, conchoidal fracture, and a specific gravity of 2.65.

Identified August 5, 2026More mineral →

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Physical properties

Hardness of 7 on the Mohs scale, typically white, clear, or grey in color, vitreous to sugary luster, trigonal crystal system, conchoidal fracture, and a specific gravity of 2.65.

Formation & geological history

Formed in hollow cavities of sedimentary or volcanic rocks where silica-rich groundwater percolates and slowly deposits microscopic quartz crystals along the cavity walls over long periods.

Uses & applications

Used for lapidary work, decorative display pieces, crystal collecting, and occasionally in metaphysical practices.

Geological facts

Geodes appear as ordinary, unassuming spherical rocks on the outside, but cracking them open reveals a sparkling interior lined with quartz crystals.

Field identification & locations

Can be identified by their rounded, knobby exterior texture and hollow interior cavity lined with sparkling crystals. Commonly found in limestone formations, volcanic ash beds, and deserts worldwide.