fossil

Fossil Coral

Scleractinia / Hexagonaria

AI-generated identification · may be incorrect

Hardness 3-4 on Mohs scale, typically white, beige, or grey with a dull to vitreous luster and distinct honeycomb or star-like septa structures.

Identified November 15, 2026More fossil →

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Physical properties

Hardness 3-4 on Mohs scale, typically white, beige, or grey with a dull to vitreous luster and distinct honeycomb or star-like septa structures.

Formation & geological history

Formed from ancient marine invertebrate skeletons that accumulated in shallow tropical seas and fossilized through mineral replacement over millions of years.

Uses & applications

Used primarily in decorative items, jewelry making, lapidary arts, and as educational specimens for fossil collectors.

Geological facts

Many fossil corals, particularly Petoskey stones, are glacial drift polished by ice sheets during the Pleistocene epoch.

Field identification & locations

Easily identified in the field by characteristic radial patterns and corallites; commonly found in limestone-rich sedimentary strata worldwide.

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Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

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Likely fossil oyster shell

Fossilized bivalve shell; exact species cannot be identified from the image

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Invertebrate fossil / Trace fossil

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Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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Fossiliferous limestone (likely a crinoidal or shell-fragment limestone)

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

sedimentary

Porous limestone pebble

Calcite-rich limestone (primarily CaCO₃); exact identification is uncertain from the image

sedimentary