fossil

Fossil shell fragment, likely brachiopod or bivalve

Indeterminate bioclast; possible Brachiopoda or Mollusca

AI-generated identification · may be incorrect

Small, brown-gray, weathered fragment with visible ribbing and layered shell texture; likely calcite or aragonite, Mohs hardness about 3–4, dull to earthy luster, and no obvious crystal cleavage.

Identified September 20, 2026More fossil →

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Physical properties

Small, brown-gray, weathered fragment with visible ribbing and layered shell texture; likely calcite or aragonite, Mohs hardness about 3–4, dull to earthy luster, and no obvious crystal cleavage.

Formation & geological history

A shelled marine organism was buried in sediment and mineralized or preserved, commonly during the Paleozoic or Mesozoic eras; the fragment’s exact age cannot be determined from the image.

Uses & applications

Primarily a teaching or collecting specimen; complete, identifiable fossils may have modest decorative or educational value, but fragments have little industrial use.

Geological facts

The radial ribs likely represent shell ornamentation, useful for distinguishing fossil groups. Brachiopods commonly have bilateral shell symmetry, while bivalves usually have two matching valves.

Field identification & locations

Look for repeated ribs, growth lines, a distinct hinge, and symmetry; a dilute acid test may fizz if exposed calcium carbonate, but it can damage the specimen. Common in marine limestone and shale deposits worldwide.