sedimentary
Limestone
Calcium Carbonate (CaCO3)
Hardness of 3 on the Mohs scale, colors range from white, gray, tan, to yellow, dull to earthy luster, fine-grained to coarse crystal structure, excellent cleavage, specific gravity of 2.7
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Physical properties
Hardness of 3 on the Mohs scale, colors range from white, gray, tan, to yellow, dull to earthy luster, fine-grained to coarse crystal structure, excellent cleavage, specific gravity of 2.7
Formation & geological history
Formed by the accumulation and compaction of organic remains like shells and coral, or chemical precipitation of calcium carbonate in marine environments over millions of years
Uses & applications
Used extensively in construction (cement, concrete, road base), agriculture (soil conditioning), and manufacturing of glass and paper
Geological facts
Limestone often contains fossils of ancient marine organisms and forms spectacular cave systems through dissolution by acidic groundwater
Field identification & locations
Easily identified by its characteristic fizz when a drop of dilute hydrochloric acid is applied due to the release of carbon dioxide gas; commonly found worldwide in sedimentary basins
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