Limestone is a sedimentary rock comprising mainly calcium carbonate in the form of calcite. It is formed either by precipitation in marine waters or by evaporation of water in caves. Stalactites, an icicle-shaped calcium carbonate deposit on cave ceilings are also known as Travertine. It is mainly used as construction material and road base. More than 50% of limestone is made of calcium carbonate, along with small quantities of quartz, pyrite, and siderite. Properties such as Strong, dense and abrasion resistance make it suitable for dimension stone, roofing granules, Portland cement, flux stone etc.