fossil

Crinoid Stem Fossil

Crinoid columnal (Echinodermata)

AI-generated identification · may be incorrect

Hardness: 3-4 (Calcite), Color: Grey, brown, or black, Luster: Vitreous to dull, Crystal structure: Trigonal (calcite composition), Cleavage: Perfect rhombohedral in calcite, Specific Gravity: 2.7

Identified August 5, 2026More fossil →

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Physical properties

Hardness: 3-4 (Calcite), Color: Grey, brown, or black, Luster: Vitreous to dull, Crystal structure: Trigonal (calcite composition), Cleavage: Perfect rhombohedral in calcite, Specific Gravity: 2.7

Formation & geological history

Formed through the fossilization of marine invertebrate animals (crinoids, commonly known as sea lilies) during the Paleozoic to Mesozoic eras, primarily in marine limestone environments.

Uses & applications

Collected by fossil enthusiasts, used in educational displays, and sometimes studied for paleoenvironmental reconstructions.

Geological facts

Crinoids are animals related to starfish and sea urchins. Their stems are composed of stacked disk-like segments called columnals, which frequently break apart and fossilize individually, sometimes referred to locally as 'Indian beads' or 'St. Cuthbert's beads'.

Field identification & locations

Found in limestone and shale deposits worldwide, often identified by their cylindrical shape and central canal or star-shaped pattern visible on the ends of the segments.