sedimentary

Crinoid Columnal Fossil

Class Crinoidea (Echinodermata); usually calcite replacement (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 (calcite); Color: Tan, white, or gray; Luster: Dull to earthy; Structure: Disc-shaped or cylindrical with a central hole (lumen) and radial symmetry; specific gravity approx 2.7.

Hardness: 3 (calcite)
Color: Tan, white, or gray
Luster: Dull to earthy

Identified March 7, 2026More sedimentary →

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Physical properties

Hardness: 3 (calcite); Color: Tan, white, or gray; Luster: Dull to earthy; Structure: Disc-shaped or cylindrical with a central hole (lumen) and radial symmetry; specific gravity approx 2.7.

Formation & geological history

Formed from the skeletal remains of 'sea lilies' (marine echinoderms). These segments lived during the Paleozoic era (approx. 250-500 million years ago) in shallow, warm sea environments.

Uses & applications

Primarily for geological study, education, and fossil collecting. Historically used as 'Saint Cuthbert's beads' for jewelry or rosaries.

Geological facts

Also known as 'fairy coins' or 'star stones,' crinoids are not plants but animals related to starfish and sea urchins. They were so abundant that they formed entire limestone layers.

Field identification & locations

Identify by looking for the 'cheerio' or button shape with a hole in the center. Common in limestone outcrops in the Midwest USA, UK, and Morocco. Look for them in creek beds and quarries.