sedimentary
Limestone
Calcium Carbonate (CaCO3)
Hardness: 3 on Mohs scale, Color: White, gray, tan, or yellowish, Luster: Dull to earthy, Crystal structure: Hexagonal (calcite), Cleavage: Perfect in three directions, Specific Gravity: 2.71
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Physical properties
Hardness: 3 on Mohs scale, Color: White, gray, tan, or yellowish, Luster: Dull to earthy, Crystal structure: Hexagonal (calcite), Cleavage: Perfect in three directions, Specific Gravity: 2.71
Formation & geological history
Formed through the accumulation of skeletal fragments of marine organisms such as coral, algal, and foraminifera, typically in shallow, calm, warm marine waters over millions of years.
Uses & applications
Widely used in construction as a building material, as an aggregate for road bases, as a primary component of portland cement, and in agriculture to neutralize acidic soils.
Geological facts
Limestone often contains fossils of ancient marine life. Famous structures such as the Great Pyramid of Giza and parts of the Empire State Building utilize limestone.
Field identification & locations
Can be easily identified in the field by its characteristic effervescence (fizzing) when a weak acid like vinegar is applied to its surface. Found worldwide.
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