
mineral
Quartz Geode
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 7 on the Mohs scale, Color: White to clear sparkling crystals with an outer chalcedony/limestone rind, Luster: Vitreous (glassy) to earthy, Crystal structure: Trigonal, Cleavage: None, Specific Gravity: 2.65
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Physical properties
Hardness: 7 on the Mohs scale, Color: White to clear sparkling crystals with an outer chalcedony/limestone rind, Luster: Vitreous (glassy) to earthy, Crystal structure: Trigonal, Cleavage: None, Specific Gravity: 2.65
Formation & geological history
Formed in hollow cavities in sedimentary and volcanic rocks where silica-rich groundwater precipitates quartz crystals over thousands to millions of years.
Uses & applications
Commonly collected as mineral specimens, used in decorative items, lapidary arts, and sometimes in metaphysical practices.
Geological facts
Geodes start as bubbles in volcanic rock or animal cavities in sedimentary rock. Over time, mineral-rich water seeps through the outer shell, slowly growing crystals inward toward the hollow center.
Field identification & locations
Easily identified by its rounded exterior nodule shape and sparkling crystal-lined interior cavity when broken open. Found globally, famously in locations like Morocco, Brazil, and the USA (Indiana, Iowa, Kentucky).