Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-12-01T02:47:59.352Z Has data issue: false hasContentIssue false

X-ray topography of natural tetrahedral diamonds

Published online by Cambridge University Press:  05 July 2018

A. Yacoot
Affiliation:
Dept. of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX
M. Moore
Affiliation:
Dept. of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX

Abstract

The symmetry of diamond is still sometimes questioned. Most people agree that diamond belongs to the space group Fdm and therefore to point group . Some however, on account of the existence of a few natural tetrahedral diamonds, have assigned diamond to the point group 3m. We report here on an X-ray topographic investigation, using both conventional and synchrotron sources, of eleven natural tetrahedral diamonds. Two large specimens (from the Alpheus Williams' collection) were studied and found to consist of two portions, unequal in size, that were twinned on a (111) plane. Another diamond (from Professor R. A. Howie's collection) was found to contain two non-parallel (111) twin planes with the diamond filling the space between them, giving the crystal a tetrahedral morphology. Four tetrahedral diamonds (selected by Tolansky) were shown to be either twinned on a (111) plane, or cleavage fragments consisting of one component of a made or single crystals that had been plastically deformed. Similar results were found for some diamonds from the Argyle Mine. Our findings are consistent with diamond belonging to the holosymmetric class () rather than to the hemihedral class (3m).

Type
Mineralogy
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1993

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

*

Now at National Physical Laboratory, Teddington, Middlesex TW11 0LW, UK.

References

Bragg, W. H. and Bragg, W. L. (1913) Proc. Roy. Soc., A89, 277-91.Google Scholar
Chadwick, J. (1987) R.T.Z. Review, 4, 37.Google Scholar
Clackson, S. G. (1989) X-ray Studies of Defects in Diamond and Gallium Arsenide. Ph.D. Thesis, Univ. of London.Google Scholar
Donnay, G. and Donnay, J. D. H. (1981) Soy. Phys. Crystallogr., 26, 729–32.Google Scholar
Fersmann, A. and Goldschmidt, V. (1911) Der Dia- mant. Carl Winters, Heidelberg.Google Scholar
Frank, F. C. (1949) Disc. Faraday Soc., 5, 4854.Google Scholar
Frank, F. C. (1958) In Growth and Perfection in Crystals (Doremus, Roberts and Turnbull, eds.), J. Wiley and Sons.Google Scholar
Frank, F. C. and Lang, A. R. (1965) in The Physical Properties of Diamond. (R. Berman, ed.), Clarendon Press.Google Scholar
Hornstra, J. (1958) J. Phys. Chem. Solids, 5, 129–41.Google Scholar
Lang, A. R. (1957) Acta Metallurgica, 5, 358–64.Google Scholar
Lang, A. R. (1958) J. Applied Physics, 29, 597–8.Google Scholar
Lang, A. R. (1978) In Diffraction and Imaging Techniques in Material Science. (S. Amelinckx, R. Gevers, and J. Van Landuyt, eds.), North Holland Publishers.Google Scholar
Lang, A. R. (1979) In Physical Properties of Diamond. (J. Field, ed.), Academic Press.Google Scholar
Moore, M. (1973) Dissolution, Defects and Disorder in Diamond and Diamond-like Substances. PhD. Thesis, Univ. of Bristol.Google Scholar
Moore, M. (1988) Industrial Diamond Review, 49, 5964.Google Scholar
Moore, M. and Lang, A. R. (1974) J. Crystal Growth, 26, 133–9.Google Scholar
Seager, A. F. (1979) Mineral. Mag., 43, 377–87.Google Scholar
Shafranovskii, I. I., Alyavdin, V. F., and Botkunov, A. I. (1966) Zap. Vses. Mineral. Obshch., 95, 123–7.Google Scholar
Sutton, J. R. (1928) Diamond: A Descriptive Treatise. Murby, London.Google Scholar
Tolansky, S. (1971) Diamond Conference, Cambridge, paper 29 (unpublished).Google Scholar
Williams, A. F. (1932) The Genesis of the Diamond, Vol. I & II, E. Benn, London.Google Scholar
Yacoot, A. (1990) X-ray Studies of Diamond: Morphology and Radiation Counting Behaviour. PhD. Thesis, Univ. of London.Google Scholar