Feldspar is a mineral, and it can exhibit both cleavage and fracture. Cleavage refers to the tendency of a mineral to break along specific planes of weakness, resulting in smooth, flat surfaces. Feldspar typically exhibits good cleavage in one or two directions. Fracture, on the other hand, refers to the random breaking of a mineral that does not follow any specific patterns. Feldspar can also fracture in irregular or conchoidal (shell-like) patterns when subjected to significant force.«Geological and mathematical framework for failure modes in granular rock »