Fuller's Earth
in mineralogy, smectite; an argillaceous earth, used by fullers to absorb the oil or grease with which woolen cloth has been treated during previous manufacture. Also kaolinite. In geology, a stratum belonging to the Lower Oölite, in some instances, lying in certain localities, just below the in certain loca localities, just below the Great Oölite, while in others it is wholly absent. Its characteristic fossil is an oyster (Ostrea acuminata). In all about 60 mollusca are found in the fuller's earth, 50 being lamellibranchiate bivalves, 10 brachiopoda, three gasteropods, and seven or eight cephalopoda.