fossil

Bivalve seashell (likely cockle or ark clam)

Calcareous shell composed chiefly of aragonite (CaCO₃); exact species cannot be determined confidently from the image

AI-generated identification · may be incorrect

Hardness about 3–4 Mohs; white to pale gray, ribbed radial sculpture, dull to pearly luster, and layered fibrous shell structure. It shows bilateral-valve symmetry and likely retains original shell material rather than being a mineral crystal.

Identified August 27, 2026More fossil →

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At a glance

Common name: Bivalve seashell (likely cockle or ark clam)
Scientific name: Calcareous shell composed chiefly of aragonite (CaCO₃); exact species cannot be determined confidently from the image
Category: fossil
Identified: August 27, 2026
Method: Standard

AI Estimated Value

Typically $1–$10 for a common beach specimen; up to about $20–$50 if unusually large, intact, or scientifically identified.

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

Formation & geological history

Formed biologically by a marine bivalve, with aragonite secreted in successive growth layers; the specimen appears modern or subfossil, not necessarily geologically fossilized. Found in coastal sand and shallow marine sediments of many ages.

Uses & applications

Used as a natural curiosity, educational specimen, craft material, and occasionally in shell jewelry or décor; not generally valuable as a gemstone.

Geological facts

Radial ribs strengthen the shell and may help it resist wave and sediment forces. The visible hinge-side residue may be adhering sediment or encrustation.

Field identification & locations

Identify by the fan-shaped, strongly ribbed valve and concentric growth lines; confirm species using the hinge, interior teeth, and matching valve. Common on sandy beaches worldwide; avoid collecting where protected.