sedimentary

Fossiliferous limestone with shell fragments

Bioclastic calcarenite; predominantly calcite (CaCO₃), with fossil mollusk material

AI-generated identification · may be incorrect

Typically Mohs hardness 3, white to cream or gray, dull to sugary/vitreous on fresh shell surfaces, and nonfoliated. Calcite commonly fizzes strongly with dilute hydrochloric acid; visible curved shell layers and porous cement are diagnostic.

Identified September 10, 2026More sedimentary →

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At a glance

Common name: Fossiliferous limestone with shell fragments
Scientific name: Bioclastic calcarenite; predominantly calcite (CaCO₃), with fossil mollusk material
Category: sedimentary
Identified: September 10, 2026
Method: Standard

AI Estimated Value

Typically $5–$25 for a small common specimen; $30–$100+ if the fossils are unusually well preserved, identifiable, or from a documented locality.

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 and carbonate skeletal debris accumulated, were compacted, and cemented on a shallow seafloor. The exact age cannot be determined from the photograph; such limestones range from Paleozoic to Quaternary.

Uses & applications

Used as building stone, aggregate, cement and lime feedstock; attractive fossil-bearing pieces are collected or displayed rather than used as gemstones.

Geological facts

The specimen appears dominated by recrystallized or broken shell fragments in a carbonate matrix, possibly including bivalve or gastropod material. Acid testing on an inconspicuous area helps distinguish it from silicate rock.

Field identification & locations

Common in marine sedimentary basins worldwide, including Florida, the Bahamas, Mediterranean regions, and many coastal platforms. Look for fossils, powdery carbonate surfaces, low density, and vigorous acid effervescence.