Limestone is a sedimentary rock that is precipitated out of seawater. Most sea creatures produce calcite calcium carbonate ; the shells of small sea animals, corals, even fish bones. As these animals go through their lifecycle calcite is deposited on the ocean floor. After time the pressure of the ocean water as well as the evaporation of the ocean water this binds these materials together to form a Limestone. Limestone is generally white to gray but can have different colors depending on other materials deposited when Limestone is formed. Limestone is very soft and very subject to subject to staining and etching. In ancient times Limestone was the most common stone building material. In present time it is most commonly used as block building material, slab counters, and floor and wall tile. Limestone is not recommended for floors and walls. Because of its absorbent nature and softness, it is not the best option for counters and flooring with high usage. Much more durable as well as attractive alternatives are Porcelain tile, Travertine stone, or Marble for floors. Granite slab is the best choice for stone counters and vanities.