sedimentary

Weathered fossil-bearing limestone

Bioclastic limestone, chiefly calcite (CaCO₃), possibly containing a brachiopod or coral fossil

AI-generated identification · may be incorrect

Gray-brown, fine- to medium-grained, dull to weakly earthy luster, with an apparent shell-like fossil impression and weathered cavities. Calcite has Mohs hardness 3, rhombohedral cleavage, and specific gravity about 2.7; it should fizz with dilute hydrochloric acid.

Identified September 13, 2026More sedimentary →

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At a glance

Common name: Weathered fossil-bearing limestone
Scientific name: Bioclastic limestone, chiefly calcite (CaCO₃), possibly containing a brachiopod or coral fossil
Category: sedimentary
Identified: September 13, 2026
Method: Standard

AI Estimated Value

Typically $5–$25 as a common hand specimen; professionally prepared, clearly identifiable fossils may sell for $30–$150 or more.

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, skeletal debris, or carbonate mud accumulated and lithified in an ancient shallow sea. The specimen’s exact geologic age cannot be determined from the photograph; fossil-bearing limestones range from Paleozoic to Cenozoic.

Uses & applications

Used as aggregate, dimension stone, cement and lime feedstock; attractive fossiliferous pieces are collected or used decoratively, but this rough specimen has limited commercial value.

Geological facts

The raised and recessed textures may represent a weathered fossil, possibly a brachiopod, bivalve, or colonial coral, though the image is insufficient for confident identification.

Field identification & locations

Look for visible fossil outlines, a relatively soft surface, and vigorous acid effervescence; distinguish it from dolostone, which reacts weakly unless powdered. Common in former shallow-marine regions worldwide, including the Appalachians, Midwest, and European carbonate belts.