sedimentary
Limestone
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectHardness of 3 on Mohs scale; typically gray, white, or tan; dull to earthy luster; fine-grained crystal structure; effervesces in dilute hydrochloric acid.
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Physical properties
Hardness of 3 on Mohs scale; typically gray, white, or tan; dull to earthy luster; fine-grained crystal structure; effervesces in dilute hydrochloric acid.
Formation & geological history
Formed through the accumulation of skeletal fragments, coral, algal, and fecal debris, or chemical precipitation, primarily in shallow marine environments over millions of years.
Uses & applications
Widely used in construction as building stone, crushed stone for road base, production of cement, and agricultural soil conditioning.
Geological facts
Limestone often contains well-preserved fossils of ancient marine life and forms spectacular cave systems via dissolution by acidic groundwater.
Field identification & locations
Easily identified by its soft nature and strong fizz reaction with acid. Found globally in sedimentary basins and ancient sea beds.
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