Limestone is a sedimentary rock composed primarily of the mineral calcite (calcium carbonate, CaCO₃). It is a fundamental and versatile industrial raw material with a wide range of applications. Its primary use is in the construction industry, where it is crushed and used as an aggregate in concrete and asphalt, and as a dimension stone. It is also the key raw material for the production of lime (calcium oxide) and cement through calcination. In agriculture, finely ground limestone is applied as a soil conditioner to neutralize acidity. It serves as a filler in numerous products including paints, plastics, and paper. Furthermore, it is used as a flux in steelmaking, in flue gas desulfurization systems, and as a source of calcium carbonate in various chemical processes. Limestone is generally considered non-toxic, but dust inhalation during processing can be an irritant. Its properties, such as purity, color, and particle size, vary depending on its geological formation, which determines its suitability for specific end-uses.