sedimentary

Fossiliferous limestone (likely ammonite/gastropod-bearing)

Bioclastic limestone; predominantly calcite (CaCO₃)

AI-generated identification · may be incorrect

Identified August 12, 2026More sedimentary →

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At a glance

Common name: Fossiliferous limestone (likely ammonite/gastropod-bearing)
Scientific name: Bioclastic limestone; predominantly calcite (CaCO₃)
Category: sedimentary
Identified: August 12, 2026
Method: Standard

AI Estimated Value

Approximately $10–$50 as a common polished or shaped fossil limestone; $50–$150+ if the fossil preservation, locality, or display quality is exceptional.

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

Brown, weathered, rounded specimen with abundant orange-brown fossil shell impressions or cross-sections in a fine-grained matrix; likely Mohs 3, dull to earthy luster, non-cleaved, and moderate density (~2.5–2.7). Calcite-rich material should fizz with dilute hydrochloric acid, though weathering or coatings may weaken the reaction.

Formation & geological history

Forms when marine or freshwater shells accumulate, become compacted, and are cemented by calcite. The specimen’s exact age cannot be determined visually; fossil-bearing limestones range from Paleozoic to Cenozoic and occur in former seabeds.

Uses & applications

Used as decorative stone, educational material, and fossil collecting specimens; limestone is also important for cement, aggregate, and lime production. Value is mainly aesthetic and depends on fossil visibility and provenance.

Geological facts

The curved, coiled markings resemble small ammonites or gastropods, but a precise fossil identification requires close examination or preparation. Brown coloration likely reflects iron-oxide staining or organic-rich matrix.

Field identification & locations

Common in sedimentary basins and quarry exposures worldwide. Look for visible shell symmetry, carbonate fizz, and a lack of glassy volcanic texture; avoid assuming it is a meteorite or metal-bearing rock from color alone.