Limestone has many important uses. It is the chief source of lime. It wears better than sandstone, is more easily shaped than granite, and weathers from nearly white to a beautiful gray. Oolitic limestone, quarried in Lawrence, Monroe, and Owen counties in Indiana, is a particularly fine building stone. Bedford, Ind., is an important limestone quarrying center.
Crushed limestone is used on macadam roads.
Farmers use ground limestone to neutralize soil acids that attack calcium and other salts needed by plants. Such protection occurs naturally when soils have a limestone foundation. Travertine limestone and calcareous tufa consist of calcium carbonate deposited from hard water. Stalactites and stalagmites in caves are formed in the same way. Limestone rock is often riddled with caves because water and carbon dioxide dissolve the limestone.