sedimentary
Limestone
Calcium carbonate (CaCO3)
AI-generated identification · may be incorrectMohs hardness 3, color ranges from white to gray or tan, vitreous to earthy luster, effervesces strongly in dilute hydrochloric acid.
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Physical properties
Mohs hardness 3, color ranges from white to gray or tan, vitreous to earthy luster, effervesces strongly in dilute hydrochloric acid.
Formation & geological history
Formed through the accumulation of organic skeletal fragments like coral and shells, or chemical precipitation in marine environments over millions of years.
Uses & applications
Widely used in construction as building stone, as an aggregate for road bases, and in the manufacture of cement and lime.
Geological facts
Limestone often contains well-preserved fossils and underlies famous cave systems formed by acidic groundwater dissolution.
Field identification & locations
Easily identified by its softness and characteristic fizz when tested with acid; found abundantly worldwide in sedimentary basins.
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Sedimentary limestone with invertebrate fossil imprint
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