How can a mineral display both cleavage and fracture?

Because of the atomic structure of the mineral, cleavage is a growth plane; consequently, it is an easy plane to "cleave-along," meaning the mineral prefers to break along this plane.

If the crystal grew with a dislocation in the lattice, this may act as a weak point, so a fracture could occur along it. A fracture can occur in any direction, but typically a fracture will occur if it is more energetically favorable.

Accordingly, a fracture can occur regardless of the atomic structure of the mineral, and cleavage is peculiar to the mineral (based on the structure).

A mineral can display both cleavage and fracture if it has planes of weakness in its crystal structure, allowing it to break along specific cleavage planes, while also exhibiting irregular breakage in directions not related to the crystal structure, which is referred to as fracture.