sedimentary
Limestone
Calcium Carbonate (CaCO3)
Hardness: 3 on the Mohs scale, Color: White, gray, tan, yellow, or brown, Luster: Earthy to dull, Crystal structure: Trigonal (as the mineral calcite), Cleavage: Perfect rhombohedral cleavage, Specific Gravity: 2.7 to 2.9
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Physical properties
Hardness: 3 on the Mohs scale, Color: White, gray, tan, yellow, or brown, Luster: Earthy to dull, Crystal structure: Trigonal (as the mineral calcite), Cleavage: Perfect rhombohedral cleavage, Specific Gravity: 2.7 to 2.9
Formation & geological history
Formed through the accumulation and compaction of organic remains like shells, coral, and algal debris, or through the chemical precipitation of calcium carbonate from water in marine environments.
Uses & applications
Widely used in the manufacturing of cement, as a building material, in road construction, agricultural soil treatment, and as a chemical feedstock.
Geological facts
Limestone often contains well-preserved fossils of ancient marine organisms and makes up about 10% of the total volume of all sedimentary rocks on Earth.
Field identification & locations
Can be easily identified by its characteristic fizz when a drop of dilute hydrochloric acid is applied, due to the release of carbon dioxide gas. Found worldwide in sedimentary basins.
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