Title: diamond
Long Title: IUPAC Gold Book - diamond
DOI: 10.1351/goldbook.D01671
Status: current

Definition
An allotropic form of the element carbon with cubic structure (space group \(O_{h}^{7}- Fd3m\)) which is thermodynamically stable at pressures above \(6\ \rm{GPa}\) at room temperature and metastable at atmospheric pressure. At low pressures diamond converts rapidly to graphite at temperatures above \(1900\ \rm{K}\) in an inert atmosphere. The chemical bonding between the carbon atoms is covalent with \(\mathrm{sp}^{3}\) hybridization.

Note
There is also a hexagonal diamond-like structure of the element carbon (lonsdaleite).

Related Terms
- carbon: https://goldbook.iupac.org//terms/view/C00821
- graphite: https://goldbook.iupac.org//terms/view/G02684
- hybridization: https://goldbook.iupac.org//terms/view/H02874
- inert: https://goldbook.iupac.org//terms/view/I03026
- metastable: https://goldbook.iupac.org//terms/view/M03872
- stable: https://goldbook.iupac.org//terms/view/S05900

Source
- PAC, 1995, 67, 473. 'Recommended terminology for the description of carbon as a solid (IUPAC Recommendations 1995)' on page 487 (https://doi.org/10.1351/pac199567030473)

Other Outputs
- html: https://goldbook.iupac.org/terms/view/D01671/html
- json: https://goldbook.iupac.org/terms/view/D01671/json
- xml: https://goldbook.iupac.org/terms/view/D01671/xml

Citation: Citation: 'diamond' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.D01671
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Accessed: 2026-04-18T23:21:19+00:00