sedimentary

Fossiliferous limestone

Calcite-rich bioclastic limestone (mostly calcium carbonate, CaCO₃)

AI-generated identification · may be incorrect

Gray, fine-grained matrix with pale fossil or shell fragments; calcite has Mohs hardness 3, vitreous to dull luster, and rhombohedral cleavage. The slab’s texture is consistent with fossil-bearing limestone, though individual fossils are indistinct in the image.

Identified October 8, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed when carbonate mud and marine shell fragments accumulated on a seafloor and lithified; age cannot be determined from the image and may range widely.

Uses & applications

Used as building and paving stone, cement and lime feedstock, and as a collectible fossil-bearing specimen.

Geological facts

Limestone commonly fizzes with dilute hydrochloric acid because calcite releases carbon dioxide.

Field identification & locations

Look for shell-like fragments in a gray carbonate matrix; common in former marine sedimentary basins worldwide. Estimated value: about $5–$30 for an ordinary hand specimen, depending on size and fossil detail.