Varieties of limestone
There are many varieties of limestone based on the composition of limestone.
Chalk A soft limestone that is white or grey in colour which is mainly formed from calcareous shell remains of microscopic marine organisms.
Coquina A poorly cemented limestone that is composed mainly of broken shell debris.
Fossiliferous limestone A limestone with prominent and abundant fossils.
Oolitic limestone Limestone composed mainly of calcium carbonate oolites, spheres concentric precipitates of calcium carbonate.
Travertine Limestone formed by precipitation method mainly in caves.
Tufa Precipitation of limestone at hot springs or lake shore.