Fissility refers to the property of a rock or mineral to split easily into thin, flat layers. Some common synonyms for fissility include cleavage, fracture, shatterability, scissility, splittability, and cleavability. Cleavage is the tendency of a mineral to break along flat, smooth planes, while fracture describes the uneven or irregular break of a mineral or rock. Shatterability and splittability both describe the ease at which a rock or mineral can be broken into smaller pieces or split apart. Finally, cleavability is another synonym that refers specifically to the ease at which a mineral can be split along its natural crystal lattice planes.