This rock is made up of the mineral calcite, and it formed from the remains of organisms that lived in water

Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of themineral calcite ... Most of them are found in shallow water areas between 30 degrees north ... Chalk: A fine-grained, light-colored limestone formed from the calcium carbonate skeletal remains of tiny marineorganisms.