gemstone
Tumbled Grey Agate
Silicon dioxide (Chalcedony variety), SiO2
Hardness of 6.5 to 7 on the Mohs scale, grey color with subtle banding, waxy to vitreous luster, cryptocrystalline crystal structure, conchoidal fracture, specific gravity around 2.60 to 2.65.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, grey color with subtle banding, waxy to vitreous luster, cryptocrystalline crystal structure, conchoidal fracture, specific gravity around 2.60 to 2.65.
Formation & geological history
Forms primarily in cavities of volcanic and metamorphic rocks through the deposition of silica-rich groundwater solutions over millions of years.
Uses & applications
Used in jewelry, decorative items, tumbled pocket stones, and metaphysical practices.
Geological facts
Agate has been prized since ancient times for amulets and ornaments, famously used by the ancient Greeks and Romans for intaglio rings.
Field identification & locations
Identified by its waxy luster, hardness capable of scratching glass, and microcrystalline structure often showing translucent banding. Found worldwide.
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