sedimentary
Limestone
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectMohs hardness 3, light grey to brownish-grey color, dull to sub-vitreous luster, fine-grained microcrystalline matrix with faint shell fragments, vigorous effervescence in dilute hydrochloric acid
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Physical properties
Mohs hardness 3, light grey to brownish-grey color, dull to sub-vitreous luster, fine-grained microcrystalline matrix with faint shell fragments, vigorous effervescence in dilute hydrochloric acid
Formation & geological history
Formed in warm, shallow marine environments from the accumulation and compaction of organic debris like shells, coral, and algal remains, as well as chemical precipitation of calcite
Uses & applications
Extensively used in construction, aggregate for concrete, dimension stone, lime production, cement manufacturing, soil conditioning, and industrial chemical processes
Geological facts
Limestone accounts for about 10% of the total volume of all sedimentary rocks. It frequently contains abundant marine fossils and forms dramatic karst landscapes and cave systems worldwide
Field identification & locations
Easily identified by its soft nature (can be scratched by steel) and strong reaction to acid. It is ubiquitous in exposed sedimentary bedrock and road cuts across former shallow sea regions
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