Rock Identifier

fossil

Belemnite Fossil

Belemnitella (Rostrum)

AI-generated identification · may be incorrect

Hardness of 3-4 on the Mohs scale, typically brown to beige in color, vitreous to dull luster, and possesses a solid, bullet-shaped calcite structure.

Identified November 14, 2026More fossil →

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Physical properties

Hardness of 3-4 on the Mohs scale, typically brown to beige in color, vitreous to dull luster, and possesses a solid, bullet-shaped calcite structure.

Formation & geological history

Formed during the Mesozoic era when internal calcified shells of extinct squid-like cephalopods became fossilized in marine sedimentary environments.

Uses & applications

Valued primarily by fossil collectors, used in biostratigraphy to date rock layers, and educational displays.

Geological facts

Commonly referred to as "thunderbolts" in folklore due to the mistaken belief that they fell from the sky during lightning storms.

Field identification & locations

Easily identified by its distinctive bullet or cigar shape and fibrous calcite cross-section, commonly found in Cretaceous chalk deposits worldwide.

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Likely fossil oyster shell

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

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Fossil

Invertebrate fossil / Trace fossil

Crinoid Stem Fossil in Matrix (Phylum Echinodermata, Class Crinoidea) — fossil

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)) — sedimentary

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) — sedimentary

Porous limestone pebble

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