fossil

Fossilized bivalve shell fragment

Fossil mollusk shell, likely a pectinid or related bivalve; original shell composed mainly of aragonite or calcite, now partly mineralized

AI-generated identification · may be incorrect

Gray-beige, layered and ribbed, with a dull to slightly pearly luster and apparent bilateral shell symmetry. Hardness is roughly 3–4 Mohs; specific gravity commonly 2.6–2.8, though mineral replacement may alter these values.

Identified August 20, 2026More fossil →

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At a glance

Common name: Fossilized bivalve shell fragment
Scientific name: Fossil mollusk shell, likely a pectinid or related bivalve; original shell composed mainly of aragonite or calcite, now partly mineralized
Category: fossil
Identified: August 20, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common fragment; $30–$150 or more if unusually complete, attractive, 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

A marine bivalve shell was buried in sediment and preserved through compaction, cementation, and partial mineral replacement. Its exact geological age cannot be determined from the photograph, but similar fossils range from Paleozoic to Cenozoic deposits.

Uses & applications

Primarily a teaching, display, and collecting specimen; polished fossil shells may be used decoratively or in jewelry. It has little industrial value as an individual specimen.

Geological facts

The repeated ridges and curved layered structure are characteristic of shell growth rather than ordinary sedimentary banding. Fossil shells commonly preserve original growth lines and may retain calcite or aragonite textures.

Field identification & locations

Look for consistent ribs, shell curvature, growth lines, and a natural hinge or layered fracture; dilute acid may fizz if carbonate remains. Common in marine limestone, shale, and sandstone worldwide.