Olith

Olith, also known as oolite or oölite, is a sedimentary rock. It is composed of spherical, or near-spherical, grains called ooids. These ooids are typically formed by the precipitation of calcium carbonate around a nucleus, such as a shell fragment or a grain of sand. The grains grow outwards in concentric layers, similar to the growth of an onion. This process usually occurs in shallow, agitated marine waters where the ooids are kept in constant motion by wave and current action, allowing for even coating.

Oliths are often found in association with other carbonate rocks and can form extensive deposits. The color of oolitic limestone can vary depending on the impurities present, but it is commonly light gray, tan, or pink. The texture is typically smooth due to the rounded nature of the ooids. Famous examples of oolitic limestone formations include the Great Bahama Bank and parts of the Indiana Limestone, which has been widely used as a building material. The study of oolitic rocks provides valuable insights into past marine environments and geological processes.