sedimentary
Geode
Quartz-lined nodule
AI-generated identification · may be incorrectHardness of 7 on Mohs scale, grayish exterior with crystalline quartz interior, vitreous luster, trigonal crystal structure.
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Physical properties
Hardness of 7 on Mohs scale, grayish exterior with crystalline quartz interior, vitreous luster, trigonal crystal structure.
Formation & geological history
Formed through the infiltration of mineral-rich groundwater into cavities within sedimentary or volcanic rocks over millions of years.
Uses & applications
Popular in mineral collecting, lapidary arts, and ornamental home decor.
Geological facts
Geodes often contain hidden crystal interiors that develop as silica precipitates layer by layer on cavity walls.
Field identification & locations
Identify by their rounded, nodular exterior and hollow interior lined with sparkling crystals; commonly found in limestone formations.
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