sedimentary
Limestone
Limestone (primarily composed of Calcium Carbonate, CaCO3)
Hardness of 3 on the Mohs scale, color typically ranges from white, tan, gray, to yellow, dull to earthy luster, fine-grained to coarse crystalline texture, exhibits good cleavage along crystal planes when crystalline, specific gravity around 2.7.
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Physical properties
Hardness of 3 on the Mohs scale, color typically ranges from white, tan, gray, to yellow, dull to earthy luster, fine-grained to coarse crystalline texture, exhibits good cleavage along crystal planes when crystalline, specific gravity around 2.7.
Formation & geological history
Formed primarily from the accumulation of skeletal fragments of marine organisms such as coral, algal, and foraminifera, as well as chemical precipitation of calcium carbonate from water in shallow marine environments over millions of years.
Uses & applications
Widely used in construction as building stone, as an aggregate for road bases, as a raw material for manufacturing cement and lime, in agriculture to neutralize acidic soils, and in various chemical and industrial applications.
Geological facts
Limestone often contains fossils of ancient marine life. Famous geological formations like the white cliffs of Dover are composed almost entirely of chalk, a soft variety of limestone.
Field identification & locations
Can be easily identified in the field by its characteristic fizz or effervescence when a drop of dilute hydrochloric acid is applied due to the release of carbon dioxide gas.
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