fossil

Fossil-bearing limestone or reef limestone

Bioclastic limestone, chiefly calcite (CaCO₃), with possible encrusting bryozoans or corals

AI-generated identification · may be incorrect

Gray, cream, and brown porous carbonate rock with visible fossil/encrustation textures; calcite has Mohs hardness 3, vitreous to earthy luster, rhombohedral cleavage, and reacts vigorously with dilute hydrochloric acid. The specimen appears weathered and irregular rather than crystalline.

Identified September 11, 2026More fossil →

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At a glance

Common name: Fossil-bearing limestone or reef limestone
Scientific name: Bioclastic limestone, chiefly calcite (CaCO₃), with possible encrusting bryozoans or corals
Category: fossil
Identified: September 11, 2026
Method: Standard

AI Estimated Value

About $5–$30 for a common specimen; $30–$100+ if the fossil structures are clearly identified, attractive, and well-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

Forms from accumulated marine skeletal debris and reef organisms that lithify into limestone, commonly during Paleozoic–Cenozoic marine episodes; the exact age cannot be determined from the image. Surface cavities and coatings likely reflect later weathering or mineral growth.

Uses & applications

Used as aggregate, cement and lime feedstock, building stone, and educational or decorative fossil material; this small irregular specimen is mainly collectible.

Geological facts

The pale branching or spotted textures may represent bryozoans, corals, shell fragments, or later calcite crusts. Exact fossil identification requires a closer view or thin section.

Field identification & locations

Common in former shallow-marine regions worldwide, including limestone belts and coastal cliffs. Test an inconspicuous fresh surface with dilute acid, inspect fossil geometry with magnification, and avoid confusing calcite coatings with quartz.