sedimentary

Limestone with Fossil

Sedimentary limestone, calcium carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on the Mohs scale. Color: Off-white, grey, or tan. Luster: Dull to earthy. Crystal structure: Trigonal (calcite). Cleavage: Perfect rhombohedral cleavage. Specific gravity: 2.71.

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

Identified August 5, 2026More sedimentary →

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Physical properties

Hardness: 3 on the Mohs scale. Color: Off-white, grey, or tan. Luster: Dull to earthy. Crystal structure: Trigonal (calcite). Cleavage: Perfect rhombohedral cleavage. Specific gravity: 2.71.

Formation & geological history

Formed through the accumulation and compaction of organic remains such as shells, coral, and algae, or chemical precipitation of calcium carbonate in shallow marine environments, typically over millions of years.

Uses & applications

Used in construction, production of cement, road base, agricultural soil conditioning, and as dimension stone.

Geological facts

Limestone often preserves ancient marine fossils like crinoids, brachiopods, and ammonites, providing a detailed record of prehistoric ocean life.

Field identification & locations

Found worldwide in sedimentary basins, quarries, and coastal outcrops. Easily identified by its reaction to dilute hydrochloric acid (effervescence) and visible fossil fragments.