fossil

Fossilized crinoid stem segment (probable)

Crinoidea indeterminate; commonly fossil crinoid columnals of *Encrinus* or related taxa

AI-generated identification · may be incorrect

Pale gray-white, porous, and composed of numerous radiating or stacked calcite plates; Mohs hardness about 3, vitreous to pearly luster, with prominent cleavage and specific gravity near 2.7. The image appears to show two weathered columnal fragments rather than a complete plant-like fossil.

Identified August 13, 2026More fossil →

Explore Fossilized crinoid stem segment (probable) in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Crinoids are marine echinoderms whose calcitic skeletons were buried and lithified in shallow-marine limestone, commonly during the Paleozoic (about 541–252 million years ago) and Mesozoic eras. Diagenesis preserved the segmented stems and ossicles.

Uses & applications

Primarily a geological collectible, educational specimen, or decorative fossil; calcitic fossil material is not generally used industrially or as jewelry except in cabochons and curios.

Geological facts

Crinoid stems are often called “penny stones” or “St. Cuthbert’s beads.” Each stem was made of many disk- or barrel-shaped ossicles connected by soft tissue.

Field identification & locations

Identify by repeated segmented geometry, radial symmetry, and a central lumen; dilute hydrochloric acid should fizz on exposed calcite. Common in fossiliferous limestones worldwide, especially the United States and Europe.