fossil

Fossil bivalve shell

Bivalvia; shell composed mainly of calcium carbonate (typically aragonite and/or calcite)

AI-generated identification · may be incorrect

Cream-colored, rounded shell with fine concentric growth lines and two valves; hardness is about 3–4 Mohs, with a pearly to dull luster. The specimen appears intact, but species and precise mineral composition cannot be determined from the image alone.

Identified September 27, 2026More fossil →

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Physical properties

Formation & geological history

Bivalves formed their shells in marine or freshwater environments; fossilization occurs when shells are buried and preserved or mineral-replaced in sediment. No geological age can be established from the image.

Uses & applications

Collected as a natural-history specimen and sometimes used for display or craft decoration; its small size and uncertain provenance limit reliable valuation.

Geological facts

Growth lines record shell growth, though they do not necessarily correspond one-to-one with years.

Field identification & locations

Look for paired valves, a hinge, and concentric growth lines; fossil shells occur in sedimentary deposits worldwide. This shell’s polished-looking, regular surface may indicate a modern shell rather than a fossil.