sedimentary
Limestone
Sedimentary Rock (Primarily CaCO3)
Hardness of 3 on the Mohs scale, typically gray, tan, or white in color, dull to earthy luster, fine-grained to coarse crystal structure, specific gravity around 2.7.
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Physical properties
Hardness of 3 on the Mohs scale, typically gray, tan, or white in color, dull to earthy luster, fine-grained to coarse crystal structure, specific gravity around 2.7.
Formation & geological history
Formed from the accumulation of skeletal fragments of marine organisms such as coral, algal, and molluscan remains, typically in shallow marine environments over millions of years.
Uses & applications
Widely used in construction as building material, an aggregate for the base of roads, as an ingredient in making cement, and in agricultural soil conditioning.
Geological facts
Limestone often contains fossils of ancient marine life and is prone to chemical weathering, forming extensive cave systems and karst topography.
Field identification & locations
Can be easily identified in the field by its characteristic effervescence (fizzing) when a drop of weak hydrochloric acid or vinegar is applied.
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