Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. Most limestone is composed of skeletal fragments of marine organisms such as coral or foraminifera. Limestone is a raw material for cement. TAMIN’s Periyanagalur mine is located in Ariyalur District and its total extent is 12.745 Hects. The mine can process 1500 tonnes ore per day.