fossil

Fossiliferous limestone with silicified fossil material

Bioclastic limestone; likely marine mollusk/coral fragments, locally replaced by chalcedony or calcite

AI-generated identification · may be incorrect

Gray to tan, irregularly banded and knobby, with visible shell-like fossil structures and small cavities; dull to waxy luster. Hardness is variable, about 3 for calcite-rich areas and up to 7 where silicified; calcite-rich portions fizz in dilute hydrochloric acid.

Identified September 11, 2026More fossil →

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At a glance

Common name: Fossiliferous limestone with silicified fossil material
Scientific name: Bioclastic limestone; likely marine mollusk/coral fragments, locally replaced by chalcedony or calcite
Category: fossil
Identified: September 11, 2026
Method: Standard

AI Estimated Value

Typically $10–$50 for a hand specimen; $50–$150 or more if the fossils are exceptionally distinct, rare, or attractively polished.

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 accumulated marine skeletal debris cemented into limestone, probably Paleozoic–Mesozoic in age; later groundwater may have silicified or recrystallized portions. Commonly develops in shallow warm-marine carbonate environments.

Uses & applications

Used mainly as a fossil and geological collectible; similar limestone is used for aggregate, cement, building stone, and ornamental work, while silicified pieces may be polished.

Geological facts

The contrasting dark matrix and tan fossil/cement zones suggest recrystallization or partial replacement after burial. Fossil identification would require a closer view of diagnostic shell or coral structures.

Field identification & locations

Look for recognizable marine fossils, carbonate fizz, and a mixed calcite–silica texture; common sources include marine sedimentary basins worldwide. Avoid acid testing on valuable surfaces.