fossil

Bivalve shell fossil or modern shell

Calcareous bivalve shell, composed mainly of calcium carbonate (typically aragonite and/or calcite); species cannot be determined from this view

AI-generated identification · may be incorrect

White, layered shell with concentric growth lines and a pointed umbo; hardness about 3–4 Mohs. The image shows one valve, but does not establish whether it is fossilized or recent.

Identified October 8, 2026More fossil →

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At a glance

Common name: Bivalve shell fossil or modern shell
Scientific name: Calcareous bivalve shell, composed mainly of calcium carbonate (typically aragonite and/or calcite); species cannot be determined from this view
Category: fossil
Identified: October 8, 2026
Method: Standard

AI Estimated Value

Typically under $1–$10 for a small common shell; higher value requires unusual species, preservation, provenance, or preparation.

Not an official valuation

AI estimate for general interest only — not an appraisal. Actual value depends on condition, provenance, and market demand. Verify with a professional before buying, selling, or insuring.

This identification was generated by AI and may contain errors. Verify important details before relying on them — and never use an AI result to judge whether a specimen is safe to handle. Read the full disclaimer

Physical properties

White, layered shell with concentric growth lines and a pointed umbo; hardness about 3–4 Mohs. The image shows one valve, but does not establish whether it is fossilized or recent.

Formation & geological history

Made by a marine bivalve secreting calcium-carbonate layers. It may be a modern beach shell or an older shell preserved in sediment; age and exact setting cannot be inferred from the photo.

Uses & applications

Collected as a natural-history specimen and sometimes used in shell crafts or decoration; not generally an industrial building material.

Geological facts

Bivalve shells grow outward from the umbo, leaving growth lines that can record interruptions in growth. Many shells are primarily aragonite, which may alter to calcite during fossilization.

Field identification & locations

Look for paired valves, a hinge and internal muscle scars to confirm bivalve identity; these features are not visible here. Common in marine sediments and shorelines worldwide; avoid acids, which dissolve carbonate shell.