fossil

Fossilized crinoid columnal (likely)

Crinoidea; commonly preserved as calcite (CaCO₃)

AI-generated identification · may be incorrect

A circular, disk-like fossil with a central lumen and radial structure, likely a crinoid stem segment; calcite has Mohs hardness 3, vitreous to pearly luster, and rhombohedral cleavage. The surrounding slab appears fossiliferous limestone with additional fragmented skeletal material.

Identified August 28, 2026More fossil →

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Physical properties

Formation & geological history

Crinoids were marine animals; their stem pieces accumulated on ancient seafloors and were lithified and commonly recrystallized during Paleozoic–Mesozoic burial. Exact age and species require locality and close examination.

Uses & applications

Primarily a teaching, collecting, and decorative specimen; fossiliferous limestone may be used as ornamental stone or aggregate, but this piece is not suitable for industrial identification from the image alone.

Geological facts

Crinoid columnals are often called “Indian beads” and can show a star-shaped lumen or radial crenulations. Their abundance in some limestones reflects dense ancient crinoid meadows.

Field identification & locations

Identify by its round segmented-stem geometry, central canal, and calcitic reaction to dilute hydrochloric acid; avoid acid testing if preservation is important. Common in Paleozoic limestones, especially the Mississippian strata of North America and equivalent marine rocks worldwide.