fossil

Fossiliferous Limestone

Fossiliferous Limestone (Sedimentary Rock)

Hardness: 3-4 (Mohs scale); Color: Gray, tan, or buff with visible organic textures; Luster: Dull to earthy; Texture: Bioclastic/clastic with visible shell fragments and pores. Reacts with dilute HCl.

Hardness: 3-4 (Mohs scale)
Color: Gray, tan, or buff with visible organic textures
Luster: Dull to earthy

Identified July 4, 2026More fossil →

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Physical properties

Formation & geological history

Formed in shallow marine environments over millions of years through the accumulation and lithification of calcium carbonate skeletal remains including crinoids, brachiopods, and bryozoans. Typically Paleozoic to Cenozoic in age.

Uses & applications

Used in construction as building stone or crushed aggregate, for making lime/cement, and as a popular specimen for educational fossil collecting.

Geological facts

Many of these rocks serve as 'lithified graveyards' for ancient sea creatures. Because they are primarily Calcium Carbonate, they play a critical role in the Earth's carbon cycle and record ancient sea-level changes.

Field identification & locations

Identify in the field by looking for a grainy, porous texture on weathered surfaces that reveals shell patterns or 'screw-like' crinoid stems. Widely found in areas with sedimentary basin outcrops across North and South America and Europe.

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