sedimentary
Limestone
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectHardness 3 on the Mohs scale, earthy dull luster, grey to light brown color, reacts with dilute hydrochloric acid, massive to fine-grained sedimentary texture.
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Physical properties
Hardness 3 on the Mohs scale, earthy dull luster, grey to light brown color, reacts with dilute hydrochloric acid, massive to fine-grained sedimentary texture.
Formation & geological history
Forms primarily in shallow, warm marine environments from the accumulation and compaction of organic debris like shells, coral, and algal remains, or by chemical precipitation of calcium carbonate.
Uses & applications
Widely used in construction as building stone, crushed stone for road base, aggregate in concrete, and as a key raw material in cement production.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It often contains abundant fossils of ancient marine organisms.
Field identification & locations
Identify in the field by its soft nature (can be scratched by a steel nail) and characteristic fizzing reaction when exposed to weak acid. Found globally in sedimentary basin formations.
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