Limestone forms when these minerals precipitate out of water containing dissolved calcium. Limestone often contains fossils, and these provide scientists with information on ancient environments and on the evolution of life.
Limestone has numerous uses: as a building material, an essential component of concrete (Portland cement), as aggregate for the base of roads, as white pigment or filler in products such as toothpaste or paints, as a chemical feedstock for the production of lime, as a soil conditioner, Limestone formations contain about 30% of the world's petroleum reservoirs. The next Process is launched into the Furnance Combustion Process from Limestone (CaCO3) to Quicklime (CaO).