sedimentary
Geode
Silicon dioxide (Quartz/Chalcedony nodule)
AI-generated identification · may be incorrectHardness 7 on Mohs scale, earthy exterior with crystalline interior, vitreous to dull luster, cryptocrystalline to macrocrystalline structure.
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Physical properties
Hardness 7 on Mohs scale, earthy exterior with crystalline interior, vitreous to dull luster, cryptocrystalline to macrocrystalline structure.
Formation & geological history
Formed in cavities of sedimentary or volcanic rocks via groundwater mineral precipitation over millions of years.
Uses & applications
Popular in lapidary work, crystal collecting, decorative display pieces, and metaphysical practices.
Geological facts
Geodes start as hollow bubbles in rock, often formed by animal burrows, tree roots, or gas pockets in lava.
Field identification & locations
Identify by their spherical, bumpy exterior and hollow interior lined with sparkling crystals when cracked open.
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