sedimentary

Fossiliferous Limestone

Fossiliferous Carbonate Rock (CaCO3)

Hardness: 3 on the Mohs scale. Color: Gray, tan, or yellowish-white. Luster: Dull to earthy. Crystal structure: Microcrystalline to cryptocrystalline calcite. Cleavage: Perfect rhombohedral in calcite crystals. Specific gravity: 2.5 to 2.7.

Hardness: 3 on the Mohs scale
Color: Gray, tan, or yellowish-white
Luster: Dull to earthy

Identified August 1, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the accumulation and compaction of organic debris, shell fragments, and coral in shallow marine environments over millions of years, typically ranging from the Paleozoic to Cenozoic eras.

Uses & applications

Used extensively in construction (as aggregate, crushed stone, and dimension stone), cement production, and as a natural historical record for paleontologists and fossil collectors.

Geological facts

Fossiliferous limestone often preserves ancient marine life such as crinoids, brachiopods, and bryozoans, making every weathered rock a snapshot of ancient shallow seas.

Field identification & locations

Easily identified by its reaction to dilute hydrochloric acid (fizzing due to calcium carbonate) and the visible fossil imprints or shell fragments embedded in the matrix.

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Banded Siltstone / Mudstone Pebble

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