Hostname: page-component-cd9895bd7-dzt6s Total loading time: 0 Render date: 2024-12-29T07:32:47.605Z Has data issue: false hasContentIssue false
  • English
  • Français

A refinement of the dickite structure and some remarks on polymorphism in kaolin minerals1

Published online by Cambridge University Press:  14 March 2018

Robert E. Newnham
Robert E. Newnham*
Affiliation:
Cavendish Laboratory, Cambridge University and Laboratory for Insulation Research, Massachusetts Institute of Technology, Cambridge, Massachusetts, U.S.A.
Get access Rights & Permissions [Opens in a new window]

Summary

The crystal structure of the clay mineral dickite (Al2Si2H4O9) has been refined to a greater accuracy than that reported in an earlier analysis. Improved lattiçe parameters are: a 5·15±0·001, b 8·940±0·001, c 14·424 ± 0·002Å., β 96° 44′± 1′. The dickite structure shows several significant distortions from the geometry of the idealized kaolin layer, including deformation and rotation of the silica tetra-hedra. The most striking features of the octahedral layer are the extremely short shared edges of 2·37 Å. Although the analysis was not sufficiently accurate to position the hydrogen atoms with certainty, a model consistent with the infrared absorption spectra is proposed. The stacking sequences of kaolin-layer minerals have been considered with reference to the structural features observed in dickite. There are thirty-six ways of superposing two kaolin layers commensurate with the OH-O bonds found in kaolinite, dickite, and nacrite. The twelve sequences showing the least amount of cation-cation superposition between consecutive kaolin layers can be used to construct two one-layer cells, kaolinite and its mirror image, and twelve two-layer cells, including dickite and nacrite. The distortions of the kaolin layer introduce secondary variations in the interlayer bonding that suggest that dickite and nacrite are the most stable of the kaolin layer structures, since they possess the shortest oxygen-hydroxyl contacts.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 32 , Issue 252 , March 1961 , pp. 683 - 704
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1961

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

1

Supported by the Nuffield Foundation, I.C.I. Ltd., and the U.S. Army Signal Corps, Office of Naval Research, and Air Force

References

Adler, (H.), Bray, (E. E.), Stevens, (N. P.), Hunt, (J. M.), Keller, (W. D)., Pickett, (E. E.), and Kerr, (P. F.), 1950. Report 8, American Petroleum Institute Project 49, Columbia University, New York.Google Scholar
Bates, (T. F.), 1959. Amer. Min., vol. 44, p. 78.Google Scholar
Berghuis, (J.), Haanappel, (IJ.), Potters, (M.), Loopstra, (B. O.), Macgillavry, (C. H.), and Veenendaal, (A. L.), 1955. Acta Cryst., vol. 8, p. 478.CrossRefGoogle Scholar
Brindley, (G. W.), 1951. X-ray identification and structure of the clay minerals, Min. Soc. Monograph, London, chap. 2.Google Scholar
Brindley, (G. W.) and Nakahira, (M.), 1958. Min. Mag., vol. 31, p. 781.Google Scholar
Brindley, (G. W.) and Robinson, (K.), 1946a. Ibid., vol. 27, p. 242.Google Scholar
Brindley, (G. W.) and Robinson, (K.) 1946b. Trans. Faraday Soc., vol. 42B, p. 198.Google Scholar
Busing, (W. R.) and Levy, (H. A.), 1958. Acta Cryst., vol. 11, p. 798.Google Scholar
Devries, (A.), 1958. Nature, vol. 181, p. 1193.Google Scholar
Farquhar, (M. C. M.) and Lipson, (H.), 1946. Proc. Phys. Soc., vol. 58, p. 200.CrossRefGoogle Scholar
Hendricks, (S. B.), 1938. Zeits. Krist., vol. 100, p. 509.Google Scholar
Henry, (N. F. M.), Lipson, (H.), and Wooster, (W. A.), 1951. The Interpretation of X-ray Diffraction Photographs. London (Macmillan and Co.), p. 161.Google Scholar
HoNess, (A. P.) and Williams, (F. J.), 1935. Amer. Min., vol. 20, p. 462.Google Scholar
Johannson, (G.), 1959. Acta Cryst., vol. 12, p. 522.Google Scholar
Lipson, (H.) and Cochran, (W.), 1953. The Determination of Crystal Structures, London (Bell & Sons Ltd.), chap. 9.Google Scholar
McDonald, (T. R. R.), 1956. Acta Cryst., vol. 9, p. 162.CrossRefGoogle Scholar
Megaw, (H. D.), 1934. Zeits. Krist., vol. 87, p. 185.Google Scholar
Nakamoto, (K.), Margoshes, (M.), and Rundle, (R. E.), 1955. Journ. Amer. Chem. Soc., vol. 77, p. 6480.CrossRefGoogle Scholar
Newnham, (R. E.) and Brindley, (G. W.), 1956. Acta Cryst., vol. 9, p. 759.; correction: ibid. 1957, vol. 10, p. 88.CrossRefGoogle Scholar
Smith, (J. V.), 1954. Acta Cryst., vo. 7, p. 479.CrossRefGoogle Scholar
Smith, (J. V.) and Yoder, (H. S.), 1956. Min. Mag., vol. 31, p. 209.Google Scholar
Weisz, (O.), Cochran, (W.), and Cole, (W. F.), 1949. Acta Cryst., vol. 2, p. 280.Google Scholar
Zoltai, (T.) and Buerger, (M. J.), 1959. Zeits. Krist., vol. 111, p. 129.CrossRefGoogle Scholar