fossil

Polished fossiliferous limestone (likely Goniatite limestone)

Fossil-bearing marine limestone, composed chiefly of calcite (CaCO₃), with visible fossil shells

AI-generated identification · may be incorrect

Polished, glossy surface; dark gray-brown matrix with pale rounded fossil cross-sections. Calcite hardness is 3 Mohs; fossils are embedded in fine-grained carbonate rock.

Identified October 11, 2026More fossil →

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At a glance

Common name: Polished fossiliferous limestone (likely Goniatite limestone)
Scientific name: Fossil-bearing marine limestone, composed chiefly of calcite (CaCO₃), with visible fossil shells
Category: fossil
Identified: October 11, 2026
Method: Standard

AI Estimated Value

About $10–$60 USD for a small polished specimen; larger or especially fossil-rich pieces may cost more.

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

Polished, glossy surface; dark gray-brown matrix with pale rounded fossil cross-sections. Calcite hardness is 3 Mohs; fossils are embedded in fine-grained carbonate rock.

Formation & geological history

Marine organisms accumulated on an ancient seafloor and were buried, compacted, and cemented into limestone; the exact geological age cannot be confirmed from the image, but similar fossil limestones range from Paleozoic to Mesozoic.

Uses & applications

Polished specimens are used for display, collecting, and lapidary items; limestone is also widely used for cement, aggregate, and building stone.

Geological facts

The circular and curved patterns appear to be fossil shell or cephalopod cross-sections exposed by cutting and polishing.

Field identification & locations

Look for repeated fossil outlines within a continuous carbonate matrix and a polished cut face; dilute acid effervesces on calcite-rich limestone. Similar material occurs in fossil-bearing limestone deposits worldwide.