sedimentary

Fossiliferous Limestone

Calcium Carbonate (CaCO3) with Bioclastic inclusions

AI-generated identification · may be incorrect

Hardness: 3-4 (Mohs scale); Color: Tan, beige, or light gray; Luster: Dull to earthy; Crystal structure: Trigonal (microcrystalline calcite); Cleavage: None (conchoidal fracture); Specific gravity: 2.3-2.7

Hardness: 3-4 (Mohs scale)
Color: Tan, beige, or light gray
Luster: Dull to earthy

Identified April 4, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed in warm, shallow marine environments where skeletal fragments of marine organisms (like mollusks, corals, or crinoids) accumulate and are lithified over millions of years through compaction and cementation.

Uses & applications

Used as a primary source of lime for cement, as building stone, agricultural soil conditioner, and commonly collected as educational fossil specimens.

Geological facts

Much of the world's architectural limestone contains visible fossils that can be hundreds of millions of years old. The Great Pyramids of Giza were originally encased in white polished limestone.

Field identification & locations

Identify by looking for visible shell or organism imprints. It will react and fizz (effervesce) when in contact with dilute hydrochloric acid due to its calcium carbonate content.