fossil

Crinoid Stem Fossil

Crinoid ossicle (phylum Echinodermata)

Hardness: 3 on Mohs scale (calcite). Color: Varies from white, grey, to tan or brownish. Luster: Vitreous to dull. Crystal structure: Trigonal (composed of single calcite crystals). Cleavage: Perfect rhombohedral cleavage.

Hardness: 3 on Mohs scale (calcite)
Color: Varies from white, grey, to tan or brownish
Luster: Vitreous to dull

Identified August 3, 2026More fossil →

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Physical properties

Formation & geological history

Formed during the Paleozoic era (particularly Mississippian and Pennsylvanian periods) when crinoids, marine animals related to starfish and sea urchins, lived in ancient shallow seas. After death, their segmented stems broke apart and were preserved in sedimentary limestone deposits.

Uses & applications

Used in fossil collecting, educational displays, and occasionally lapidary work or jewelry making when polished.

Geological facts

Crinoids are commonly known as 'sea lilies' because of their flower-like appearance. In some cultures, fossilized crinoid stems were known as 'St. Cuthbert's beads' or fairy money.

Field identification & locations

Easily identified by their circular or pentagonal shape with a central hole or star pattern. Found globally in limestone and shale formations rich in marine fossils.

Other fossil specimens

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Crinoid Stem Fossil in Matrix

Phylum Echinodermata, Class Crinoidea

fossil

Sedimentary Outcrop (Sandstone/Shale)

Sedimentary bedrock formation (variable composition)

sedimentary

Chert with Fossil Brachiopod

Microcrystalline Quartz (SiO2) with Calcitic Brachiopod inclusion

sedimentary

Crinoid Stem Fossils (Indian Beads / St. Cuthbert's Beads)

Crinoid columnal ossicles (phylum Echinodermata)

fossil

Fossilized Crinoid Stem in Limestone

Crinoidea (Class) in Calcium Carbonate (CaCO3) matrix

fossil

Fossiliferous Limestone

Limestone with embedded fossil cross-section

sedimentary