sedimentary

Fossiliferous limestone

Bioclastic carbonate rock, predominantly calcite (CaCO₃)

AI-generated identification · may be incorrect

Typically gray-brown, fine to medium grained, dull to weakly earthy luster, with visible shell or crinoid fragments; calcite hardness is about Mohs 3 and it effervesces strongly with dilute hydrochloric acid. Fossils may preserve ribbing, chambers, or shell textures in positive or negative relief.

Identified September 7, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms from accumulated marine skeletal debris that lithifies through compaction and cementation, commonly in shallow warm seas. Its age cannot be determined from the image; fossil assemblages and regional geology are required.

Uses & applications

Used as building stone, aggregate, cement and lime feedstock, and educational or decorative fossil material; attractive slabs and hand specimens have modest collector value.

Geological facts

The specimen visibly contains abundant fossil fragments, likely brachiopods, crinoids, or other marine organisms. Fossil-rich limestone records ancient marine ecosystems and can be useful for biostratigraphic correlation.

Field identification & locations

Identify by visible fossils, relatively soft surfaces, and vigorous acid fizz; it commonly occurs in marine sedimentary formations worldwide. Avoid acid testing on valuable specimens and use a tiny concealed spot.