An allotropic form of the element carbon consisting of layers of hexagonally arranged carbon atoms in a planar condensed ring system
graphene layers The layers are stacked parallel to each other in a three-dimensional crystalline long-range order. There are two allotropic forms with different stacking arrangements, hexagonal and rhombohedral. The chemical bonds within the layers are covalent with
hybridization and with a C–C distance of

. The weak bonds between the layers are metallic with a strength comparable to van der Waals bonding only.
Note:
The term graphite is also used often but incorrectly to describe
graphite materials, i.e. materials consisting of
graphitic carbon made from carbon materials by processing to temperatures greater than

, even though no perfect graphite structure is present.
Source:
PAC, 1995, 67, 473
(Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995))
on page 491
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
doi:10.1351/goldbook.