Definition of cleavage
Cleavage
i. The breaking of a mineral along its crystallographic planes, thus reflecting crystal structure.
Compare with: parting
ii. The property or tendency of a rock, usually metamorphic, to split along closely spaced, planar, aligned fractures or foliations, produced by deformation or metamorphism. See also axial-plane cleavage, slaty cleavage.
Ref: AGI
iii. In quarrying, the cleavage of rocks is often called the rift.
Ref: Nelson
Compare with: parting
ii. The property or tendency of a rock, usually metamorphic, to split along closely spaced, planar, aligned fractures or foliations, produced by deformation or metamorphism. See also axial-plane cleavage, slaty cleavage.
Ref: AGI
iii. In quarrying, the cleavage of rocks is often called the rift.
Ref: Nelson
Hill-Ledford Mine, Cave-In-Rock Mining Sub-District, Hardin County, Illinois, USA