Hostname: page-component-84b7d79bbc-4hvwz Total loading time: 0 Render date: 2024-08-04T17:21:23.789Z Has data issue: false hasContentIssue false
  • English
  • Français

The unit-cell of aenigmatite

Published online by Cambridge University Press:  14 March 2018

C. H. Kelsey  and
Duncan McKie
C. H. Kelsey
Affiliation:
Department of Mineralogy and Petrology, Downing Place, Cambridge
Duncan McKie
Affiliation:
Department of Mineralogy and Petrology, Downing Place, Cambridge
Get access Rights & Permissions [Opens in a new window]

Summary

Redetermination of the unit-cell dimensions as a 10·406 Å, b 10·813 Å, c 8·926 Å, α 104° 56′, β 96° 52′, γ 125° 19′, has shown that the hitherto accepted unit-cell of Gossner and Spielberger (1929) is in error. The morphological unit-cell of Palache (1933) is related to the new unit-cell, to a high degree of precision, by the transformation Palache → Kelsey-MeKie [001∕01½½∕½00]. Fifteen published and two new analyses indicate that the unit-cell contents approach Na+4 [Fe2-10- Ti4+2] Si4+12O2-40. The common twin axis constitutes the diad of a pseudo-monoclinic cell, the (010) plane of which is dimensionally closely related to that of pyroxenes and amphiboles. It is suggested that the aenigmatite structure is based on silicate chains of pyroxene type cross-linked by Ti4+ and Fe2+ on distinct 6-fold sites, with Na+ on sites of higher coordination number. Aenigmatite from volcanic in contrast to that from plutonic parageneses is often submicroscopically twinned and may be inverted from a high temperature monoclinic polymorph.

Type
Research Article
Information
Mineralogical magazine and journal of the Mineralogical Society , Volume 33 , Issue 266 , September 1964 , pp. 986 - 1001
Copyright
Copyright © 1964, The Mineralogical Society

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.)

References

Ahrens, (L.H.), 1952.Geochimiea Aet., vol. 2, p. 155.Google Scholar
De Andrade, (M.), 1954. Compt. Rend. 19me Internat. Géol. Cong. Algiers 1952, fasc. 20, p. 241.Google Scholar
Arsannoux, (H.), 1906. L'Étude des roehes alealines de l'Est africain. Paris.Google Scholar
Boucart, (J.) and Denaeyer, (M.E.), 1925.Compt. Rend. Aead. Sci. Pari., vol. 181, p. 1073.Google Scholar
Bowen, (N.L.), 1937.Amer. Min., vol. 22, p. 139.Google Scholar
Breithaupt, (A.), 1865.Berg- Hiittenm.-Ztg., vol. 24, p. 397.Google Scholar
Brögger, (W.C.), 1890.Zeits. Kryst. Min., vol. 16, p. 423.Google Scholar
Buerger, (M.J.), 1956. Elementary Crystallography. Wiley, New York.Google Scholar
Buerger, (M.J.), 1957. Zeits. Krist., vol. 109, p. 42.CrossRefGoogle Scholar
Buerger, (M.J.), 1960. Crystal-structure Analysis. Wiley, New York.Google Scholar
(Gorny Zhurn.), p. 740.; abstr, under Tschernik, (G.) in Neues Jahrb. Min., 1928, ReL I, p. 361.Google Scholar
Carmichael, (I. S. E.), 1962.Min. Mag., vol. 33, p. 86.Google Scholar
Delaunay, (B.), 1933.Zeits. Krist., vol. 84, p. 109.Google Scholar
Denaeyer, (E.), 1923.Compt. Rend. Acad. Sci. Pari., vol. 176, p. 1161.Google Scholar
Donnay, (J. I. H.) and Nowacki, (W.), 1954. Crystal Data. Geol. Soc. Amer. Mere. 60.Google Scholar
Ernst, (W.G.), 1962.Journ. Geol., vol. 70, p. 689.CrossRefGoogle Scholar
(Bull. Acad. Sci. Russie), ser. 6, vol. 17, p. 275. [M.A. 2-398]Google Scholar
фepcᴍaн, (A.E) 1926. Amer. Min., vol. ll , p. 289.Google Scholar
фepcᴍaн, (A.E) 1937. Minerals of the Khibina and Lovozero tundras. Acad. Sei. Press, Moscow.Google Scholar
Fioke, (B.), 1961.Tschermaks Min. PeAr. Mitt., ser.., vol. 7, p. 337.CrossRefGoogle Scholar
Fleischer, (M.), 1936.Amer. Journ. Sci., ser.., vol. 32, p. 343.CrossRefGoogle Scholar
Foerstner, (H.), 1881.Zeits. Kryst. Min., vol. 5, p. 348.Google Scholar
[Gerasimovsky (V.I.)], 1936 Cccp (Trans. Lomonossov Inst., Acad. Sci. U.S.S.R.), no. 7, p. 5.[M.A. 7-210].Google Scholar
Gossner, (B.) and Mussgnug, (F.), 1929. Centr. Min., Abt. A, p. 5.Google Scholar
Gossner, (B.) and Spielberger, (F.), 1929.Zeits. Krist., vol.72, p. I l l .Google Scholar
Gottardi, (G.), 1960.Amer. Min., vol. 45, p. 1.Google Scholar
Groth, (P.), 1883.Zeits. Kryst. Min., vol. 7, p. 607.Google Scholar
Hintze, (C.), 1897.Handbueh der Mineralogi., vol. 2.Google Scholar
Kasper, (J.S.) and Lonsdale, (K.), 1959.Internat. Tab. X-ray Cryst., vol. 2.Google Scholar
(E. E.) [Kostyleva, (E.E.)], 1930 Cccp (Trans. Mus. Min., Acad. Sci. U.I∼.S.S.), vol. 4, p. 87. [M.A. 2-35].Google Scholar
Lacrolx, (A.), 1909.Bull. Soc. fran∼. Min., vol. 32, p. 325.Google Scholar
Lacrolx, (A.), 1910.Min6ralogie de la Franc., vol. 4. Librairie Polytechnique, Paris.Google Scholar
Lorenzen, (J.), 1882.Min. Mag., vol. 5, p. 49.Google Scholar
Mckie, (D.), 1962. Ibid., vol. 33, p. 281.Google Scholar
Mckie, (D.), 1963. Ibid.,p. 635.CrossRefGoogle Scholar
Marshall, (P.), 1932.New Zealand Journ. Sci. Tech., vol. 13, p. 198.Google Scholar
Marshall, (P.), 1936.Trans. Roy. See. New Zealan., vol. 66, p. 337.Google Scholar
Megaw, (H.D.) and Kelseu, (C.H.), 1955.Min. Mag., vol. 30, p. 569.Google Scholar
Niggli, (P.), Koeirigseerger, (J.), and Parken (R. L.), 1940. Die Mineralien der Schweizeralpen. Wepf, Basel.Google Scholar
Palache, (C.), 1933.Zeits. Krist., vol. 86, p. 283.Google Scholar
Prior, (G.T.), 1928.Min. Mag., vol. 21, p. 485.Google Scholar
Smith, (W.C.), 1931.Quart. Journ. Geol. See., vol. 87, p. 212.CrossRefGoogle Scholar
Soellner, (J.), 1907. Neues Jahrb. Min., Beil.-Bd. 24, p. 475.Google Scholar
Soellner, (J.), 1909.Zeits. Kryst. Min., vol. 46, p. 518.Google Scholar
Teale, (E.O.) and S.'Alth, (W.C.), 1923.Geol. Mag., vol. 60, p. 226.CrossRefGoogle Scholar
Tomita, (J.), 1934. Journ. Shanghai Sci. Inst., sect. 2, p. 99.Google Scholar
Washington, (H.S.), 1914.Journ. Geol., vol. 21, pp. 653.and 68., vol. 22, p. 1.CrossRefGoogle Scholar
Williams, (H.), Turner, (F.J.), and Gilbert, (C.M.), 1954. Petrography. Freeman, San Francisco.Google Scholar
Williams, (J. F.), 1891. Ann. Rept. Geol. Surv. Arkansas for 1890, vol. 2.Google Scholar
Woodard, (H. H.), 1957. Journ. Geol., vol. 65, p. 61.Google Scholar
Yagi, (K.), 1953. Bull. Geol. Soc. Amer., vol. 64, p. 769.Google Scholar
Yagi, (K.), 1958. Journ. Min. Soc. Japan, vol. 3, p. 763.Google Scholar
Zussman, (J.), 1959. Acta Cryst., vol. 12, p. 309.Google Scholar
Note added in proof: After this paper had gone to press Dr. Michael Fleischer kindly drew our attention to three new analyses of aenigmatite from the Kola peninsula in I. V. Bussen and O. B. Dudkin (1962), Neither these nor two earlier analyses (one in V. I. Gerasimovsky, 1936, and the other in O. B. Boggild, Medd. Gronland, 1953, vol. 149, no. 3, p. 308) that were excluded from Table IV materially affect the conclusions drawn from the examination of unit-cell contents. In another recent paper Z. V. Shlyukova (1963) cites X-ray powder data to demonstrate the identity of eossyrite with aenigmatite.Google Scholar
(I. V. Bussen and O. B. Dudkin), CCCP (Mater. Min. Kola Peninsula, Acad. Sci. USSR), 1962, vol. 2, p. 96.Google Scholar
(Z. V. Shlyukova), CCCP (Trans. Min. Mus. Aead. Sei. USSR), 1963, no. 14, p. 262.Google Scholar