fossil

Fossilized shell-bearing limestone

Fossiliferous limestone, likely containing brachiopod or bivalve remains; exact taxon requires microscopy

AI-generated identification · may be incorrect

A brown-gray, weathered carbonate rock with visible ribbed shell impressions or fragments in a fine matrix. Calcite-rich limestone is typically Mohs 3, dull to earthy, nonmetallic, and reacts vigorously with dilute hydrochloric acid; fossils retain shell ornamentation and may show cleavage or crystalline spar.

Identified September 9, 2026More fossil →

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At a glance

Common name: Fossilized shell-bearing limestone
Scientific name: Fossiliferous limestone, likely containing brachiopod or bivalve remains; exact taxon requires microscopy
Category: fossil
Identified: September 9, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common rough fossiliferous limestone; $30–$150+ if the fossil is well-preserved, identifiable, and attractively prepared.

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 accumulated, were buried, compacted, and cemented by calcite; the specimen is likely Paleozoic or Mesozoic, but age cannot be determined reliably from the image alone. Subsequent weathering exposed the fossil surfaces.

Uses & applications

Primarily a teaching, display, and collecting specimen; fossiliferous limestone can also be used as aggregate, cement feedstock, and dimension stone when sufficiently massive.

Geological facts

The prominent radiating ribs resemble a brachiopod or bivalve, but the apparent structure may also be a mold or cross-section. Acid testing and preparation of a clean edge can distinguish calcite shell material from noncarbonate rock.

Field identification & locations

Common in ancient shallow-marine sedimentary formations worldwide, including North America, Europe, and parts of Asia. Look for repeated shell symmetry, bedding, and fizz with acid; avoid destructive testing on valuable specimens.