Rock Identifier
Ammonite (Ammonoidea) — fossil
fossil

Ammonite

Ammonoidea

AI-generated identification · may be incorrect

Hardness varies around 3.5 to 4 on Mohs scale; exhibits a distinctive planispiral shell structure with complex septa and sutures; color ranges from brown and grey to iridescent, with a pearly or vitreous luster.

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Physical properties

Hardness varies around 3.5 to 4 on Mohs scale; exhibits a distinctive planispiral shell structure with complex septa and sutures; color ranges from brown and grey to iridescent, with a pearly or vitreous luster.

Formation & geological history

Formed through the fossilization and mineral replacement of ancient marine mollusk shells in sedimentary rock layers, primarily during the Mesozoic Era.

Uses & applications

Widely utilized in paleontology, decorative display pieces, jewelry making, and as popular collector specimens.

Geological facts

Ammonites are extinct cephalopods closely related to modern octopuses and squids, serving as crucial index fossils for dating sedimentary strata.

Field identification & locations

Identified easily by their coiled, snail-like shell and intricate suture patterns; commonly found in marine sedimentary deposits globally.

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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
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Porous limestone pebble

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sedimentary
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Weathered fossil bone fragment (identification uncertain)

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

fossil