cleavage (geology)

In geology, cleavage refers to the tendency of minerals or rocks to split along specific planar surfaces. These surfaces are parallel to layers of atomic arrangement within the mineral, resulting in smooth, flat sheets or sheets that occur naturally. Cleavage forms during the mineral’s crystallization or as a result of later pressure and stress, and it can reveal valuable information about the rock's history. The quality and pattern of cleavage help geologists identify minerals and understand the geological processes that shaped the rock.