sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectMohs hardness 7, white to clear color, vitreous luster, trigonal crystal system, conchoidal fracture, specific gravity 2.65.
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Physical properties
Mohs hardness 7, white to clear color, vitreous luster, trigonal crystal system, conchoidal fracture, specific gravity 2.65.
Formation & geological history
Formed in hollow cavities of sedimentary or volcanic rocks via groundwater mineral precipitation over millions of years.
Uses & applications
Popular in lapidary work, decorative display pieces, crystal collecting, and jewelry.
Geological facts
Geodes form when mineral-rich water deposits silica inside ancient gas bubbles or animal burrows within rock.
Field identification & locations
Identify by a rough, bumpy exterior and a hollow interior lined with sparkling quartz crystals. Found globally, notably in Brazil and the US.
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