Limestone

White Limestone is sedimentary rock composed primarily of calcium carbonate. Limestone in origin can be hemogenni (chemically precipitated), nutrient (largely composed of remnants of organisms - the phytoplankton and zooplankton, shells, skeletal particles, etc.).

Limestone is one of the most widely used  material in constructions. Furthermore, naturally, limestones  is used for industrial production of lime, carbon dioxide, calcined soda. Add in the production of iron ore by acid.