sedimentary

Crinoid Stem Fossil

Crinoid columnal (Class Crinoidea)

AI-generated identification · may be incorrect

Hardness: 3-4 (calcite) or 7 (if silicified); Color: Tan, gray, or white; Luster: Dull to earthy; Structure: Cylindrical segments often with a star-shaped or circular central hole (lumen).

Hardness: 3-4 (calcite) or 7 (if silicified)
Color: Tan, gray, or white
Luster: Dull to earthy

Identified June 27, 2026More sedimentary →

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Physical properties

Hardness: 3-4 (calcite) or 7 (if silicified); Color: Tan, gray, or white; Luster: Dull to earthy; Structure: Cylindrical segments often with a star-shaped or circular central hole (lumen).

Formation & geological history

Formed from the mineralized remains of marine animals related to starfish. These segments were part of the stalk that anchored the animal to the sea floor during the Paleozoic era (approx. 250-500 million years ago).

Uses & applications

Commonly used as educational specimens, in decorative stonework, and as a popular item for amateur fossil collectors and jewelry.

Geological facts

Crinoids are often called 'sea lilies' because they look like flowers, but they are actually animals. In some cultures, fossilized stem segments were known as 'St. Cuthbert's beads' and used to make rosaries.

Field identification & locations

Look for small, stacked disc-like wheels or 'button' shapes in limestone. They are extremely common in the Midwest United States and areas with ancient seafloor deposits.