https://doi.org/10.1351/goldbook.D01671
An allotropic form of the element
carbon
with cubic structure (space group Oh7Fd3m) which is thermodynamically
stable
at pressures above 6 GPa at room temperature and
metastable
at atmospheric pressure. At low pressures diamond converts rapidly to
graphite
at temperatures above 1900 K in an
inert
atmosphere. The chemical bonding between the carbon atoms is covalent with sp3
hybridization
.
Note:
There is also a hexagonal diamond-like structure of the element carbon (lonsdaleite).
Source:
PAC, 1995, 67, 473. (Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)) on page 487 [Terms] [Paper]