sedimentary
Limestone
Calcium Carbonate (CaCO3)
Hardness: 3 on Mohs scale, Color: Varies from white, gray, yellow to black, Luster: Earthy to dull, Crystal Structure: Hexagonal (calcite), Specific Gravity: 2.7
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Physical properties
Hardness: 3 on Mohs scale, Color: Varies from white, gray, yellow to black, Luster: Earthy to dull, Crystal Structure: Hexagonal (calcite), Specific Gravity: 2.7
Formation & geological history
Formed through the accumulation and compaction of organic remains like shells, coral, and algae, or through the chemical precipitation of calcium carbonate from water in marine environments over millions of years.
Uses & applications
Widely used in construction as building stone, as an aggregate for roads, in the production of cement and lime, and in agriculture to neutralize acidic soils.
Geological facts
Limestone often contains fossils of ancient marine organisms. Famous structures like the Great Pyramids of Giza were built using limestone blocks.
Field identification & locations
Can be easily identified in the field by its characteristic fizzing or effervescence when a drop of weak hydrochloric acid or vinegar is applied due to the release of carbon dioxide.
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