fossil

Weathered fossil shell or crinoid fragment

Likely fossilized echinoderm or bivalve fragment; exact taxon indeterminate from the image

AI-generated identification · may be incorrect

Small tan, rounded, highly weathered specimen with dark brown mineral-filled fractures and granular texture; likely calcite-rich, Mohs hardness about 3, dull to slightly waxy luster, and no obvious crystal cleavage.

Identified September 6, 2026More fossil →

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Physical properties

Formation & geological history

A marine carbonate fossil later mineralized or preserved in limestone, then weathered free from its host rock; age cannot be determined visually, but such fossils commonly range from Paleozoic to Mesozoic.

Uses & applications

Primarily a teaching or collecting specimen; carbonate fossils have little industrial value individually, though fossil limestone is used as aggregate and cement feedstock.

Geological facts

The radial or segmented pattern may indicate an echinoderm element, while the overall form could also be a worn bivalve or gastropod fragment.

Field identification & locations

Look for repeated radial symmetry, shell growth lines, pores, or crinoid columnal segmentation; vinegar may weakly fizz if exposed calcite is present, but this test can damage it. Common in limestone exposures and gravel derived from marine sedimentary rocks.