what is limestone made from
Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO 3) in the form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters.It is usually an organic sedimentary rock that forms from the accumulation of shell, coral, algal and fecal debris. rock known as tufa is a limestone formed by evaporation at a hot spring, lake shore, or other area. Limestone is by definition a rock that contains at least 50% calcium carbonate in the form of calcite by weight. All limestones contain at least a few percent other materials.