fossil

Limestone fossil or crinoid stem

Fossiliferous limestone / Echinodermata

Hardness 3 on Mohs scale, yellowish-brown color due to weathering, dull luster, and distinct circular fossil segment structures.

Identified November 15, 2026More fossil →

Get a report just like this from any photo, free.

Physical properties

Hardness 3 on Mohs scale, yellowish-brown color due to weathering, dull luster, and distinct circular fossil segment structures.

Formed from the accumulation of organic carbonate marine remains in ancient shallow seas millions of years ago.

Collected as a geological curiosity, educational fossil specimen, and used in paleontology studies.

Fossiliferous limestones often preserve ancient marine biodiversity, capturing fragments of crinoids, brachiopods, and corals.

Identify by its distinctive circular ring fossil segments and effervescence when tested with dilute hydrochloric acid.

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

Fossil

Invertebrate fossil / Trace 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)

Porous limestone pebble

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