fossil

Fossiliferous limestone with a bivalve fossil

Calcareous sedimentary rock; likely molluscan shell fossil, composed chiefly of calcite (CaCO₃)

AI-generated identification · may be incorrect

Typically Mohs 3, tan to gray, dull to weakly pearly, with visible layered shell ribs and a granular limestone matrix; calcite may effervesce in dilute hydrochloric acid. The specimen appears naturally weathered and partly fossilized.

Identified September 10, 2026More fossil →

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At a glance

Common name: Fossiliferous limestone with a bivalve fossil
Scientific name: Calcareous sedimentary rock; likely molluscan shell fossil, composed chiefly of calcite (CaCO₃)
Category: fossil
Identified: September 10, 2026
Method: Standard

AI Estimated Value

About $5–$25 USD as a common hand specimen; $30–$100+ if the fossil is unusually complete, well-prepared, or specifically 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 when marine shells accumulated, were buried, and mineralized or preserved in carbonate sediment; age cannot be determined from the image, but such limestone commonly ranges from Paleozoic to Cenozoic. The shell structure suggests a marine depositional environment.

Uses & applications

Used mainly for education, paleontology, and collecting; limestone is also quarried for cement, aggregate, and building stone, though this small specimen has no industrial value.

Geological facts

The ribbed structure is characteristic of a bivalve or brachiopod shell, but exact identification requires the opposite valve, hinge, and diagnostic anatomy. Fossils can retain original shell ornament even after recrystallization.

Field identification & locations

Look for carbonate fizz, low hardness, shell symmetry, growth lines, and a contrasting matrix; common in marine limestone outcrops worldwide. Avoid strong acid on valuable specimens, as it can damage the surface.