Fun Facts about LimestoneLimestone is Missouri's most abundant commercial mineral. It was created 320-500 million years ago by the deposition of calcium and magnesium on ocean floors. Almost all limestone formations in the state contain fossils of animals that lived in the ocean, providing evidence of interesting land-sea changes which in this part of the country has undergone in the geologic past.
Limestone's unique physical and chemical properties allow it to have many uses. Hundreds of beautiful, historic structures in Missouri were built with it, including Daniel Boone's home, the Old St. Louis Cathedral near the Arch, and even the State Capitol Building! Today, it has extensive use as one of the raw materials in Portland cement. Specialty uses include the manufacturing of pharmaceuticals, toothpaste, paint, paper, caulking and glass. Common antacids are virtually 100% finely-ground limestone. Farmers use limestone to neutralize acidity in their soils. Counties use crushed limestone to provide an all-weather driving surface on unpaved roads. However, it's most commonly used as construction aggregate.