fossil

Fossiliferous limestone, likely with a coral or stromatoporoid fossil

Calcite (CaCO₃) limestone containing fossilized marine skeletal material

AI-generated identification · may be incorrect

Gray, fine- to medium-grained, dull to weakly waxy surface with raised branching or cellular fossil textures; calcite has Mohs hardness 3, rhombohedral cleavage, and reacts vigorously with dilute hydrochloric acid. The specimen appears water-worn and may be partially silicified or weathered.

Identified September 6, 2026More fossil →

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At a glance

Common name: Fossiliferous limestone, likely with a coral or stromatoporoid fossil
Scientific name: Calcite (CaCO₃) limestone containing fossilized marine skeletal material
Category: fossil
Identified: September 6, 2026
Method: Standard

AI Estimated Value

About $5-$30 for a common hand specimen; $50-$150 or more if the fossil is distinctive, well preserved, and locally 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 from carbonate mud and marine organisms on an ancient shallow seafloor, probably during the Paleozoic or Mesozoic Era; later lithification and erosion exposed the fossil. Exact age and fossil identity require microscopy or acid testing.

Uses & applications

Primarily a collecting and educational specimen; limestone is widely used for cement, aggregate, building stone, and agricultural lime, while attractive fossils may be polished or displayed.

Geological facts

The branching relief may represent colonial coral, bryozoan, or stromatoporoid growth rather than mineral crystal patterns. Fossil limestone preserves ancient marine ecosystems and can record past sea levels and climates.

Field identification & locations

Look for repeated biological geometry, contrasting calcite matrix, and fizz with dilute acid; a hand lens can reveal coral pores or bryozoan chambers. Common in former shallow-marine limestone belts worldwide, including the Great Lakes and many Paleozoic outcrops.