Why does graphite split easily between its layers?

In materials science, graphite splits easily between its layers because of the specific nature of its crystal structure. Graphite consists of parallel sheets of carbon atoms arranged in fused hexagonal rings. Within each layer, the atoms are held together by strong covalent bonds.1

However, the distance between these individual layers is relatively large, which prevents localized bonding between them. Instead, the layers are held together only by weak van der Waals forces—an attractive force resulting from interactions between the electrons of one atom and the nuclei of neighboring atoms. Because these interlayer forces are significantly weaker than the covalent bonds within the sheets, the layers can slide past one another or separate with minimal effort. This structural characteristic is responsible for graphite's characteristic softness, lubricity, and its tendency to exhibit ready cleavage.12