fossil

Fossil bivalve shell

Likely fossilized cockle or other marine bivalve; exact genus requires locality and internal features

AI-generated identification · may be incorrect

Layered, ribbed shell with off-white to tan coloration and pearly/subdued luster; original calcite/aragonite has likely been mineralized. Typical shell hardness is about 3–4 Mohs, with strong growth lines and radial ribs; specific gravity commonly 2.6–2.9.

Identified August 19, 2026More fossil →

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At a glance

Common name: Fossil bivalve shell
Scientific name: Likely fossilized cockle or other marine bivalve; exact genus requires locality and internal features
Category: fossil
Identified: August 19, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common small specimen; $30–$100+ if unusually old, exceptionally preserved, or accompanied by verified locality information.

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

A marine mollusk shell accumulated in sediment and was buried, compacted, and variably fossilized during diagenesis. Its geological age cannot be determined from the photograph; similar specimens range from Cenozoic to much older deposits.

Uses & applications

Primarily a collectible, educational specimen, or natural-history display piece; not generally used for jewelry or construction. Polished fossil shells may be incorporated into decorative objects.

Geological facts

The concentric bands record growth stages, while the ribs strengthened the shell against waves and predators. Fossil shells may retain original mineral material or be replaced by calcite, silica, or iron-bearing minerals.

Field identification & locations

Identify it by its symmetric bivalve outline, layered growth lines, and radial ribbing; a living shell is lighter and more fragile, while fossilization often adds matrix, mineral staining, or increased weight. Commonly found in marine limestones, sandstones, and coastal fossil beds worldwide.