sedimentary
Limestone (Micritic)
Sedimentary rock mainly composed of Calcium Carbonate (CaCO3)
Hardness: 3-4 (Mohs scale), Color: light grey to tan, Luster: dull to earthy, Crystal structure: microcrystalline, Cleavage: none (conchoidal fracture), Specific Gravity: 2.3-2.7
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Physical properties
Hardness: 3-4 (Mohs scale), Color: light grey to tan, Luster: dull to earthy, Crystal structure: microcrystalline, Cleavage: none (conchoidal fracture), Specific Gravity: 2.3-2.7
Formation & geological history
Formed through the accumulation of shell, algal, and fecal debris in marine environments; or via chemical precipitation from calcium-rich waters.
Uses & applications
Used widely in construction (aggregate, cement), as a road base, and as a soil conditioner in agriculture.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks on Earth. It is the primary rock type found in cave systems.
Field identification & locations
Identify in the field by applying a drop of dilute acid (like vinegar); it will effervesce (fizz). Found in ancient seabed exposures globally.
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