fossil

Fossilized Ammonite Fragment

Ammonoidea

Hardness varies from 3.5 to 4 depending on mineral replacement; displays distinct ribbed spiral chambers with pearly or mineralized luster.

Identified November 1, 2026More fossil →

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Physical properties

Hardness varies from 3.5 to 4 depending on mineral replacement; displays distinct ribbed spiral chambers with pearly or mineralized luster.

Formed through the fossilization of marine mollusks that lived during the Mesozoic Era, approximately 240 to 66 million years ago.

Used widely as educational specimens, decorative display items, jewelry, and collector's pieces.

Ammonites are extinct marine cephalopods closely related to modern octopuses and squids rather than to chambered nautiluses.

Identified by their distinctive coiled, chambered shell structures; commonly found in marine sedimentary rock layers worldwide.

Probable fossil-bearing rock or mineral concretion

Unidentified carbonate-rich concretion with a possible fossil inclusion

Likely fossil oyster shell

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

Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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

Bioclastic limestone, composed chiefly of calcite (CaCO₃)

Porous limestone pebble

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

Weathered fossil bone fragment (identification uncertain)

Fossilized bone; exact taxon and mineral composition cannot be determined from the image