sedimentary
Quartz Geode / Druzy Quartz Node
Silicon Dioxide (SiO2)
Mohs hardness of 7. Colors range from yellowish-tan and brown exterior to clear/white crystalline interior. Vitreous to dull exterior luster, bright vitreous interior druzy luster. Trigonal crystal system. Specific gravity of 2.65.
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Physical properties
Mohs hardness of 7. Colors range from yellowish-tan and brown exterior to clear/white crystalline interior. Vitreous to dull exterior luster, bright vitreous interior druzy luster. Trigonal crystal system. Specific gravity of 2.65.
Formation & geological history
Formed in secondary cavities (vugs) within sedimentary or igneous rocks where silica-rich groundwater precipitated microcrystalline quartz and macrocrystalline quartz druse over long periods.
Uses & applications
Used primarily as decorative lapidary material, educational specimens, gemstone display pieces, and for mineral collecting.
Geological facts
Small cavities inside such rocks are called geodes or vugs, lined with tiny sparkling quartz crystals known as druzy quartz.
Field identification & locations
Look for lightweight, rounded stones with rough exteriors that produce a sparkling reflection when light hits small vugs or fractures. Frequently found in riverbeds, limestone formations, and gravel deposits worldwide.
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