sedimentary
Limestone
Calcium Carbonate (CaCO3)
Hardness of 3 on the Mohs scale, colors range from white, gray, yellow to brown, dull to earthy luster, fine-grained to coarse crystal structure, excellent cleavage in some forms, specific gravity around 2.7.
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Physical properties
Hardness of 3 on the Mohs scale, colors range from white, gray, yellow to brown, dull to earthy luster, fine-grained to coarse crystal structure, excellent cleavage in some forms, specific gravity around 2.7.
Formation & geological history
Formed through the accumulation of skeletal fragments of marine organisms such as coral, algal, and foraminifera, typically in shallow, warm marine waters over millions of years.
Uses & applications
Widely used in construction (as a building material and aggregate for road bases), in the production of cement, as a soil conditioner in agriculture, and in the manufacturing of glass and paper.
Geological facts
Limestone can host extensive cave systems due to its solubility in slightly acidic water, and famous structures like the Great Pyramids of Giza were built using limestone blocks.
Field identification & locations
Easily identifiable in the field by its characteristic fizz when a drop of dilute hydrochloric acid is applied, due to the release of carbon dioxide gas from calcium carbonate.
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