fossil

Fossiliferous limestone

Bioclastic carbonate rock, chiefly calcite (CaCO₃), containing a likely colonial coral or bryozoan fossil

AI-generated identification · may be incorrect

Typically Mohs hardness 3, white to gray or tan, dull to slightly crystalline luster, and no obvious cleavage; calcite commonly effervesces vigorously with dilute hydrochloric acid. The visible repeated curved/porous textures are consistent with a fossilized marine organism in limestone.

Identified August 13, 2026More fossil →

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At a glance

Common name: Fossiliferous limestone
Scientific name: Bioclastic carbonate rock, chiefly calcite (CaCO₃), containing a likely colonial coral or bryozoan fossil
Category: fossil
Identified: August 13, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common hand specimen; $30–$150 or more if the fossil pattern is unusually clear, well-prepared, and legally documented.

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 skeletal debris accumulated, was compacted, and cemented by calcite; the fossil may be Paleozoic to Mesozoic, but an exact age requires locality and identification. Common in shallow, warm-sea sedimentary environments.

Uses & applications

Used as aggregate, cement and dimension stone; attractive fossil-bearing pieces are collected and sometimes polished, though this specimen is mainly of amateur paleontological interest.

Geological facts

The patterned structures may represent tabulate coral, rugose coral, or bryozoan colonies; a clear identification requires a close-up of a freshly broken or sawn surface and locality information.

Field identification & locations

Look for embedded repeated skeletal patterns, gray-beige carbonate matrix, and acid fizz; compare with known fossils from the collecting area and avoid acid testing if preservation must be maintained. Common worldwide in marine limestone formations.