fossil

Crinoid Stem Fossil

Crinoidea (Class)

Segmented cylindrical structure, often called 'columnals'. Hardness: 3 (calcite-based). Color: Grey to tan. Luster: Dull to earthy. Structure: Disc-like stack.

Hardness: 3 (calcite-based)
Color: Grey to tan
Luster: Dull to earthy

Identified July 12, 2026More fossil →

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Physical properties

Segmented cylindrical structure, often called 'columnals'. Hardness: 3 (calcite-based). Color: Grey to tan. Luster: Dull to earthy. Structure: Disc-like stack.

Formation & geological history

Formed from the skeletal remains of marine echinoderms known as sea lilies. These calcified stems were deposited in shallow sea beds primarily during the Paleozoic era (approx. 300-500 million years ago).

Uses & applications

Collectibles, educational specimens, and occasionally used in jewelry or inlay work. Important for stratigraphic dating.

Geological facts

Crinoids are actually animals related to starfish, not plants. Their stem segments are so common in some limestone layers that they are referred to as 'encrinal limestone'.

Field identification & locations

Identify by looking for stacked, button-like rings or a central hole (lumen) in the cross-section. Commonly found in limestone outcrops and riverbeds in the Midwest US and UK.