mineral
Chalcedony (Yellow/Brown Agate Pebble)
Silicon Dioxide (SiO2)
Hardness 6.5-7 on Mohs scale, translucent to waxy luster, yellow-brown to amber color, trigonal microcrystalline structure, no cleavage, Conchoidal fracture.
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Physical properties
Hardness 6.5-7 on Mohs scale, translucent to waxy luster, yellow-brown to amber color, trigonal microcrystalline structure, no cleavage, Conchoidal fracture.
Formation & geological history
Formed through the deposition of silica-rich water solutions in cavities of sedimentary or volcanic rocks. Commonly smoothed and rounded by river, stream, or beach water action over time.
Uses & applications
Used for lapidary arts, jewelry making, tumbling, ornamental carvings, and popular among mineral collectors.
Geological facts
Microcrystalline quartz minerals like chalcedony have been used since prehistoric times to make tools due to their sharp conchoidal fracture when broken.
Field identification & locations
Easily identified by its translucent, waxy appearance, smooth water-worn surface, and scratch resistance against steel. Widely found along gravel bars, riverbeds, and beaches globally.
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