fossil

Fossiliferous Limestone with Crinoid Stem

Sedimentary Rock with Crinoidea Fossil

AI-generated identification · may be incorrect

Hardness 3-4 (Mohs), grey to dark grey matrix with a lighter, whitish segmented fossil inclusion. Dull to slightly earthy luster. Opaque.

Identified August 31, 2026More fossil →

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Physical properties

Hardness 3-4 (Mohs), grey to dark grey matrix with a lighter, whitish segmented fossil inclusion. Dull to slightly earthy luster. Opaque.

Formation & geological history

Formed in ancient marine environments where calcium carbonate accumulated from the remains of sea creatures. The inclusion is a piece of a crinoid stem, an ancient echinoderm. Often dates back to the Paleozoic era (e.g., Carboniferous period).

Uses & applications

Collectible fossil specimen, educational tool, sometimes used in lapidary arts if the matrix is hard enough.

Geological facts

Crinoids are also known as 'sea lilies' although they are animals, not plants. Their stems are made of stacked disc-like ossicles, which are very common fossils.

Field identification & locations

Identify by looking for segmented, cylindrical, or disc-like shapes embedded in limestone or shale. Commonly found in areas that were once shallow seas, such as parts of the American Midwest.