sedimentary

Fossiliferous limestone

Fossil-bearing calcitic limestone (primarily calcite, CaCO₃)

AI-generated identification · may be incorrect

Pale gray, dull to slightly crystalline matrix with rounded shell or fossil fragments; calcite hardness 3 on Mohs scale, rhombohedral cleavage, and commonly reacts with dilute acid. The visible rounded features may be fossils, though the image alone cannot identify them precisely.

Identified October 7, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms when calcium-carbonate shells and sediment accumulate and lithify, commonly in shallow marine settings. Its age cannot be determined from the photograph.

Uses & applications

Limestone is used for cement and lime, aggregate, building stone, and agricultural soil treatment; fossil-rich pieces are also collected and displayed.

Geological facts

Fossils in limestone can preserve evidence of ancient marine ecosystems and help geologists correlate sedimentary layers.

Field identification & locations

Look for shell-like shapes or fossil fragments embedded in a carbonate matrix; a dilute-acid fizz test supports limestone identification. Limestone occurs widely in sedimentary basins worldwide.