fossil

Fossiliferous limestone, possibly containing a brachiopod or bivalve fossil

Calcite-rich limestone (CaCO₃), with an apparent shell impression or shell fragment

AI-generated identification · may be incorrect

Gray-brown, dull to slightly earthy luster, fine-grained and rounded/weathered; calcite hardness is about 3 Mohs, with weak cleavage and specific gravity near 2.7. The pale curved feature may be fossil shell material, but the image alone cannot confirm it.

Identified August 12, 2026More fossil →

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At a glance

Common name: Fossiliferous limestone, possibly containing a brachiopod or bivalve fossil
Scientific name: Calcite-rich limestone (CaCO₃), with an apparent shell impression or shell fragment
Category: fossil
Identified: August 12, 2026
Method: Standard

AI Estimated Value

About $1–$15 for a common uncertain specimen; $20–$100+ if a clearly identifiable, well-preserved fossil is confirmed.

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 compacted marine carbonate mud and biological debris, likely during a Paleozoic–Mesozoic marine deposition; exact age requires locality and examination. Subsequent lithification and weathering produced the present surface.

Uses & applications

Used as aggregate, cement and lime feedstock, building stone, and educational/collector material; fossiliferous pieces are mainly collected rather than used decoratively.

Geological facts

Limestone commonly fizzes with dilute hydrochloric acid or strong vinegar if its surface is freshly scratched. Fossil shells may appear as raised pale forms, impressions, or mineral-filled cavities.

Field identification & locations

Look for visible shell symmetry, growth lines, or chambering and test a fresh spot for effervescence; avoid confusing weathered quartz or concretion textures with fossils. Common in former shallow-marine sedimentary basins worldwide.