Abstract
Various regions of type I diamonds have been analysed to determine intra-specimen variation in carbon isotopic abundance. We report here that generally, although not in all cases, a trend was observed from the centre to the exterior. The cores of some samples were isotopically light (enriched in 12C) whereas the edges became progressively heavier. For the specimen showing the greatest spread of δ13C values, the range observed covered almost 4‰, from −11.01 to −7.32‰. Such changes could be interpreted according to one or a combination of fractionation processes. Since diamonds exhibit a wide range of δ13C values (+2.7 to −34.4‰)1,2 and many specimens show evidence of heterogeneity, we have looked for isotopic differences between areas in individual diamonds which might reasonably be expected to have been formed in different conditions. The small scale of such internal structures in diamond requires the accurate excision of selected volumes. Such a requirement can now be met by controlled laser dissection. As a preliminary to realizing the full potential of such an approach, we have examined the exteriors and cores of coated diamonds, as representing one of the most conspicuous instances in which two distinct epochs of diamond genesis might be involved.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Rent or buy this article
Prices vary by article type
from$1.95
to$39.95
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Kovalskii, V. V. & Cherskii, N. V. Ind. Diamond Rev. 54–56 (1973).
Deines, P. Geochim. cosmochim. Acta 44, 943–961 (1980).
Seal, M. Phil Mag. (submitted).
Swart, P. K., Grady, M. M., Wright, I. P. & Pillinger, C. T. J. geophys. Res. 87, A283–A258 (1982).
Craig, H. Geochim cosmochim. Acta 12, 133–149 (1957).
Grady, M. M., Swart, P. K. & Pillinger, C. T. Meteoritics (in the press).
Gurkina, G. A., Ivanovskaya, I. N., Kaminiski, S. V. & Galimov, E. M. Geokhimiya 1897–1905 (1979).
Kamiya, Y. & Lang, A. R. Phil. Mag. 11, 347–356 (1965).
Seal, M. Phil. Mag. 13, 645–648 (1966).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Swart, P., Pillinger, C., Milledge, H. et al. Carbon isotopic variation within individual diamonds. Nature 303, 793–795 (1983). https://doi.org/10.1038/303793a0
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/303793a0
This article is cited by
-
Variations in carbon isotopic composition in the subcontinental lithospheric mantle beneath the Yangtze and North China Cratons: Evidence from in-situ analysis of diamonds using SIMS
Chinese Science Bulletin (2013)
-
Directional chemical variations in diamonds showing octahedral following cuboid growth
Contributions to Mineralogy and Petrology (2006)
-
Mantle degassing and diamond genesis: A carbon isotope perspective
Chinese Journal of Geochemistry (1994)
-
Natural occurrence of silicon carbide in a diamondiferous kimberlite from Fuxian
Nature (1990)
-
Mantle-derived fluids in diamond micro-inclusions
Nature (1988)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.