It is a sedimentary rock largely composed of the mineral calcite i.e calcium carbonate. Depending on the method of formation, it can be crystalline, clastic, granular or massive. Due to the presence of several impurities like clay, sand, organic remains iron oxide and other materials, most of the limestone represents different colors, especially on weathered surfaces. It is comparatively less resistant, readily available and easy to cut into blocks or more elaborate carving.