sedimentary
Limestone
Calcareous Sedimentary Rock (CaCO3)
Hardness: 3 on the Mohs scale, Color: Varies from white, gray, yellow to brown, Luster: Dull to earthy, Crystal structure: Microcrystalline or cryptocrystalline calcite, Cleavage: None distinct in rock form, Specific Gravity: 2.7
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Physical properties
Hardness: 3 on the Mohs scale, Color: Varies from white, gray, yellow to brown, Luster: Dull to earthy, Crystal structure: Microcrystalline or cryptocrystalline calcite, Cleavage: None distinct in rock form, Specific Gravity: 2.7
Formation & geological history
Formed from the accumulation of skeletal fragments of marine organisms such as coral, algae, and molluscs, as well as chemical precipitation of calcium carbonate in shallow marine environments over millions of years.
Uses & applications
Widely used in the construction industry as a building material, an aggregate for road bases, a primary component of Portland cement, and in agriculture for neutralizing acidic soils.
Geological facts
Limestone frequently contains well-preserved fossils of ancient marine life. Famous architectural structures like the Great Pyramids of Giza were partially constructed using limestone blocks.
Field identification & locations
Can be easily identified in the field by its characteristic fizzing or effervescence when a drop of dilute hydrochloric acid is applied due to the release of carbon dioxide.
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