The relationship between ionic bonds and cleavage is "as the ionic bond strength increases, cleavage will be more difficult".
There are ionic bonds between the minerals that held them together. Ionic bonds are the consequence of electrostatic fascination and electron exchange amongst positive and negative particles (cations and anions). Ionic bonding infers the development of requested crystalline solids and the cleavage of those solids will rely upon the quality of this bonding.