sedimentary

Likely fossiliferous limestone (possibly coral limestone)

Calcite-rich limestone, chiefly calcium carbonate (CaCO₃); the visible porous pattern may be fossil or reef structure

AI-generated identification · may be incorrect

Pale cream to white, dull to slightly sugary surface, with numerous pores and irregular fossil-like textures. Limestone is typically Mohs 3, commonly microcrystalline calcite, and may fizz in dilute acid; a photo cannot confirm the fossils or composition.

Identified October 10, 2026More sedimentary →

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Physical properties

Formation & geological history

Forms from accumulated carbonate shells, skeletal debris, or reef material in marine settings, then lithifies; its age cannot be determined from the image.

Uses & applications

Used as building stone, aggregate, and cement or lime feedstock; porous fossil-bearing pieces are also collected as curiosities.

Geological facts

Porosity and branching marks are consistent with fossil-rich carbonate, but could also reflect weathering or a naturally porous limestone texture.

Field identification & locations

Check for recognizable shell or coral structures and a vigorous fizz with dilute acid on a hidden spot. Limestone is widespread in former marine regions; value is usually about $1–$10 for a small common piece, more if fossils are clearly identifiable.