fossil

Crinoid Stem Fossil

Crinoidea (Class) / Calcite (CaCO3)

Hardness: 3 on Mohs scale (calcite replacement); Color: beige, light tan, to greyish-brown; Luster: earthy to dull; Structure: cylindrical, stacked columnals with visible disk-like segment rings; Cleavage: perfect rhombohedral where calcite is preserved.

Hardness: 3 on Mohs scale (calcite replacement)
Color: beige, light tan, to greyish-brown
Luster: earthy to dull

Identified July 25, 2026More fossil →

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Physical properties

Formation & geological history

Formed from the mineralized columnals (skeletal stem segments) of ancient sea lilies (crinoids) that lived in shallow marine environments, primarily during the Paleozoic era (Ordovician through Permian periods, roughly 250 to 480 million years ago).

Uses & applications

Popular educational fossils, lapidary material (sometimes referred to as 'Indian beads' or 'St. Cuthbert's beads'), and historical curiosities for collectors.

Geological facts

Crinoids are marine echinoderms related to starfish and sea urchins. Although they look like plants, they are animals. Individual disk segments of the stem often separate into tiny washer-like fossils known as columnals or ossicles.

Field identification & locations

Identify by its distinct cylindrical, segmented appearance resembling a stack of tiny coins or a screw thread with a small central lumen (canal). Commonly found in Paleozoic limestone deposits across North America, the UK, and Europe.

Other fossil specimens

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Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

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Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

sedimentary

Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

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Fossiliferous Limestone

Fossiliferous Calcilutite / Biomicrite

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Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

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Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary