sedimentary

Fossiliferous Limestone

Calcite-rich Fossiliferous Limestone (CaCO3)

Hardness 3 on Mohs scale, pale beige to tan weathered exterior with a fresh grey interior face, dull to earthy luster, fine-grained matrix with fossil fragments, effervesces strongly with dilute hydrochloric acid.

Identified July 26, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in warm, shallow marine environments through the accumulation and cementation of organic debris such as shell fragments, corals, and skeletal remains of marine organisms over millions of years.

Uses & applications

Widely used as building stone, aggregate for concrete and roadbeds, crushed stone for agricultural lime, cement manufacturing, and as ornamental landscaping rock.

Geological facts

Limestone covers about 10% of the Earth's total land area and forms extensive karst landscapes, including caves, sinkholes, and underground drainage systems. The Pyramids of Giza were built largely using limestone blocks.

Field identification & locations

Easily identified by its soft nature (can be scratched with a steel knife), dull granular texture, light color, presence of faint shell/fossil impressions, and violent fizzing reaction with acid. Commonly found in ancient marine basin deposits worldwide.

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Fossiliferous Concretion

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Shale and Pebble Fragment

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