Coccoliths are individual plates of calcium carbonate formed by coccolithophores (single-celled algae such as Emiliania huxleyi) which are arranged around them in a coccosphere. Formation and composition Coccoliths are formed within the cell in vesicles derived from the golgi body. When the coccolith's complete these vesicles fuse with the cell wall and the coccolith's excytosed and incorporated in the coccosphere. The coccoliths are either dispersed following death and breakup of the coccosp… (More on Coccoliths)