fossil

Fossiliferous limestone, likely coral or shell fragment

Calcitic limestone (primarily CaCO₃), containing preserved marine bioclasts

AI-generated identification · may be incorrect

Cream to yellow, fine-grained carbonate matrix with gray-green fossil cavities or fragments and dull earthy luster; calcite hardness is Mohs 3, with poor to indistinct cleavage in the rock. It should effervesce strongly in dilute hydrochloric acid or vinegar, especially on a freshly scratched surface.

Identified August 10, 2026More fossil →

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At a glance

Common name: Fossiliferous limestone, likely coral or shell fragment
Scientific name: Calcitic limestone (primarily CaCO₃), containing preserved marine bioclasts
Category: fossil
Identified: August 10, 2026
Method: Standard

AI Estimated Value

About $5-$25 for a common hand specimen; $30-$100 or more if the fossil structures are unusually clear, identifiable, and attractively prepared.

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, corals, or other carbonate organisms accumulated and lithified in shallow seas; the precise geological age cannot be determined from the photograph and may range from Paleozoic to Cenozoic.

Uses & applications

Used as building stone, aggregate, cement and lime feedstock; attractive polished pieces may be sold as decorative fossils or cabinet specimens, but this example appears modestly collectible.

Geological facts

The irregular gray-green shapes may be fossil molds, infilled cavities, or weathered mineral patches rather than a single identifiable organism. Iron staining likely produces the yellow-brown coloration.

Field identification & locations

Common in former shallow-marine regions worldwide, including Florida, the Caribbean, Mediterranean, India and parts of the Middle East. Look for visible shell/coral textures, carbonate softness, and acid fizz; confirm with a hand lens and acid test.