Mineral cleavage: property possessed by many
minerals of breaking in certain preferred direction along smooth plane
surfaces. Planes of cleavage are governed by atomic pattern and represent
direction in which atomic bonds are relatively weak.
- Rock cleavage: property possessed
by certain rocks of breaking with relative ease along parallel planes or nearly parallel
surfaces. Rock cleavage is designated as
Source: Leet, L. Don. 1982. Physical Geology, 6th Edition. Englewood Cliffs, NJ: Prentice-Hall