fossil

Fossilized bivalve shell

Bivalvia indeterminate; likely a preserved clam or cockle shell, composed mainly of calcium carbonate (CaCO₃)

AI-generated identification · may be incorrect

Layered, bilaterally symmetrical shell with fine growth lines, pale gray-tan color, and a dull to slightly pearly luster; original shell mineralogy was typically aragonite or calcite, Mohs hardness about 3–4. The specimen appears naturally mineralized or possibly an ordinary modern shell rather than a true rock.

Identified August 16, 2026More fossil →

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At a glance

Common name: Fossilized bivalve shell
Scientific name: Bivalvia indeterminate; likely a preserved clam or cockle shell, composed mainly of calcium carbonate (CaCO₃)
Category: fossil
Identified: August 16, 2026
Method: Standard

AI Estimated Value

$2–$20 for a common loose shell or indeterminate fossil; $20–$100+ if definitively identified, mineralized, rare, or attractively preserved.

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

Bivalves formed shells in marine or freshwater environments; fossilization may involve burial, compaction, and mineral replacement over thousands to millions of years. No precise age is determinable from the photograph.

Uses & applications

Fossil shells are used for education, paleontological collecting, décor, and geological display; crushed shell or limestone may be used as aggregate, soil amendment, or calcium source.

Geological facts

Growth lines record episodic shell expansion and environmental changes. The concentric layered structure is characteristic of bivalve shells, not sedimentary bedding.

Field identification & locations

Identify by the two-valve symmetry, hinge region, concentric growth rings, and shell-like curvature; a fossil is more likely if pores, mineral infill, matrix, or replacement are present. Common in marine sedimentary deposits worldwide.