sedimentary
Courthouse Agate / Coral Fossil
Silicified Coral / Chalcedony (SiO2)
AI-generated identification · may be incorrectHardness of 6.5-7 on the Mohs scale, waxy luster, and vitreous to sub-vitreous appearance. Features distinct cellular or honeycomb coral molds filled with microcrystalline quartz.
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Physical properties
Hardness of 6.5-7 on the Mohs scale, waxy luster, and vitreous to sub-vitreous appearance. Features distinct cellular or honeycomb coral molds filled with microcrystalline quartz.
Formation & geological history
Formed through the process of silicification, where ancient coral skeletons in warm marine environments were gradually replaced by silica-rich groundwater over millions of years.
Uses & applications
Prized by lapidaries and fossil collectors for cabochons, wire-wrapping, and display specimens.
Geological facts
This specimen preserves ancient marine ecosystems from prehistoric reef systems. The cellular cavities represent the skeletal structure of colonial rugose or tabulate corals.
Field identification & locations
Identifiable by its distinctive honeycomb or cellular surface texture and conchoidal fracture. Commonly found in regions with ancient limestone and chert formations, such as Florida and the American Midwest.
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