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The crystal structures of kidwellite and ‘laubmannite’, two complex fibrous iron phosphates

Published online by Cambridge University Press:  05 July 2018

U. Kolitsch
U. Kolitsch*
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien, Geozentrum, Althanstrasse 14, A-1090 Wien, Austria
*
*E-mail: uwe.kolitsch@univie.ac.at
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Abstract

The previously unknown, complex crystal structures of two fibrous ferric iron phosphate minerals have been solved using single-crystal X-ray diffraction data. The structure of a slightly arsenatian kidwellite has been refined in space group P2/c (a = 20.117(4), b = 5.185(1), c = 13.978(3)Å, β = 107.07(3)°, V = 1393.8(5)Å3, Z = 2) to R1 = 5.21%; a revision of both space group symmetry and chemical formula is proposed. The idealized formula is Na(Fe3+,M)9+x(OH)11(H2O)3(PO4)6, where M = Fe3+, Cu2+ or other metal cation, and x ≈ 0.3. The structure of a slightly arsenatian ‘laubmannite’ (as defined by Moore, 1970) has been refined in space group Pbcm (a = 5.172(1), b = 13.999(3), c = 31.083(6)Å, V = 2250.5(8)Å3, Z = 4) to R1 = 3.14%. The revised, idealized formula is (Fe3+,Fe2+,M)8+x(OH,H2O)9(-H2O)2(PO4)5, where M = Fe3+, Cu2+ or other metal cation, and x ≈ 0.1. The framework structures of both minerals are similar. Dominant building units are dimers composed of face- and edge-sharing FeO6 octahedra. Whereas kidwellite contains an additional trimer built of three corner-sharing FeO6 octahedra, ‘laubmannite’ instead contains a dimer built of two corner-sharing FeO6 octahedra. Kidwellite contains only trivalent iron, while one of the Fe sites in ‘laubmannite’ is occupied by a mixture of Fe3+ and Fe2+ in a 1:1 ratio. In both structures, the FeO6-based building units are linked via corners to PO4 tetrahedra; the M sites are located in narrow channels and have very low occupancies (~2 to 7%) and strongly distorted [6]- or [5+1]-coordinations. Close structural relations between kidwellite and ‘laubmannite’, and other fibrous iron phosphates explain observations of epitaxial intergrowths of them.

Keywords

kidwellitelaubmannitecrystal structurecrystal chemistryfibrous iron phosphates
Type
Research Article
Information
Mineralogical Magazine , Volume 68 , Issue 1 , February 2004 , pp. 147 - 165
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2004

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References

Anthony, J.W., Bideaux, R.A., Bladh, K.W. and Nichols, M.C. (2000) Handbook of Mineralogy. Vol. IV: Arsenates, Phosphates, Vanadates. Mineral Data Publishing, Tucson, Arizona, USA, 680 pp.Google Scholar
Barwood, H. (1974) Iron phosphate mineral locality at Indian Mountain, Alabama. Mineralogical Record, 5, 241–244.Google Scholar
Baur, W.H. (1981) Interatomic distance predictions for computer simulation of crystal structures. Pp. 31–52 in: Structure and Bonding in Crystals, Vol. II (O’Keeffe, M. and Navrotsky, A., editors). Academic Press, New York.CrossRefGoogle Scholar
Birch, W.D. (1990) Minerals from the Kintore and Block 14 opencuts, Broken Hill N.S.W.; review of recent discoveries, including tsumebite, kipushite and otavite. Australian Mineralogist, 5, 125–141.Google Scholar
Birch, W.D., Pring, A., Self, P.G., Gibbs, R.B., Keck, E., Jensen, M.C. and Foord, E.E. (1996) Meurigite, a new. brous iron phosphate resembling kidwellite. Mineralogical Magazine, 60, 787–793.CrossRefGoogle Scholar
Bjällerud, C.G. (1989) Phosphate minerals from the Leveäniemi iron mine, Svappavaara, Sweden. Mineralogical Record, 20, 343–346.Google Scholar
Braithwaite, R.S.W. and Corke, H. (1980) Kidwellite from Cornwall. Mineralogical Magazine, 43, 952–953.CrossRefGoogle Scholar
Brese, N.E. and O’Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallographica, B47, 192–197.CrossRefGoogle Scholar
Dietrich, R. (1978 a) Neues zur Phosphatparagenese der Grube Rotläufchen in Waldgirmes bei Wetzlar, Teil I. Aufschluss, 29, 107–124 (in German).Google Scholar
Dietrich, R. (1978 b) Neues zur Phosphatparagenese der Grube Rotläufchen in Waldgirmes bei Wetzlar, Teil II. Aufschluss, 29, 139–153 (in German).Google Scholar
Dietrich, R. (1982) Die Mineraliender Phosphatparagenese der Grube Rotläufchen. Emser Hefte, 4 (3), 22–47 (in German).Google Scholar
Dunn, P.J. (1990) Andrewsite and laubmannite formally discredited. American Mineralogist, 75, 1197–1199.Google Scholar
Frondel, C. (1949) The dufrenite problem. American Mineralogist, 34, 513–540.Google Scholar
Geipel, R. (1982) Sammeln in der Oberpfalz: Die Phosphatminerali en von Auerbach. Mineralien- Magazin, 6, 549–554. (in German).Google Scholar
Gibbs, R.B. (1991) New phosphate occurrences in southwestern New Mexico. New Mexico Geology, 13, 39–40.Google Scholar
Keller, P. (1985) Neue Mineralfunde aus dem Pegmatit von Sandamab, SWA/Namibia. Aufschluss, 36, 117–19.(in German).Google Scholar
Kolitsch, U. (1999) Evidence for the identity of meurigite and phospho. brite by transmission electron microscopy and X-ray powder diffraction. European Journal of Mineralogy, 11, Beih. No. 1, 132.Google Scholar
Kolitsch, U. (2001) The atomic arrangement of the. brous iron phosphate ‘laubmannite’ (as defined by Moore, 1970). European Journal of Mineralogy, 13, Beih. No. 1, 99.Google Scholar
Moore, P.B. (1970) Crystal chemistry of the basic iron phosphates. American Mineralogist, 55, 135–169.Google Scholar
Moore, P.B. and Ito, J. (1978) Kidwellite, NaFe3+ 9(OH)10(PO4)6·5H2O, a new species. Mineralogical Magazine, 42, 137–140.CrossRefGoogle Scholar
Moore, P.B., Kampf, A.R. and Irving, A.J. (1974) Whitmoreite, Fe2+Fe3+ 2(OH)2(H2O)4[PO4]2, a new species: Its description and atomic arrangement. American Mineralogist, 59, 900–905.Google Scholar
Northrop, S.A. (1996) Minerals of New Mexico, 3rd edition, revised by LaBruzza, F.A., University of New Mexico Press, Albuquerque, NM, USA, 346 pp.Google Scholar
Otwinowski, Z. and Minor, W. (1997) Processing of X-ray diffraction data collected in oscillation mode. Methods in Enzymology, 276, 307–326.CrossRefGoogle ScholarPubMed
Shape Software (1999) ATOMS for Windows and Macintosh V5.0.4. Kingsport, TN 37663, USA.Google Scholar
Sheldrick, G.M. (1997 a) SHELXS-97, a Program for the Solution of Crystal Structures. University of Göttingen, Germany.Google Scholar
Sheldrick, G.M. (1997 b) SHELXL-97, a program for crystal structure refinement. University of Göttingen, Germany.Google Scholar
Stanjek, H. (1983) Auerbach/Oberpfalz. Phosphatmineralien aus der Grube Leonie. Lapis, 8, 9–18. 42 (in German).Google Scholar
Vencato, I., Mascarenhas, Y.P. and Mattievich, E. (1986) The crystal structure of Fe2+Fe3+ 2(PO3OH)4 (H2O)4: a new synthetic compound of mineralogic interest. American Mineralogist, 71, 222–226.Google Scholar
Vencato, I., Mattievich, E. and Mascarenhas, Y.P. (1989) Crystal structure of synthetic lipscombite: a redetermination. American Mineralogist, 74, 456–460.Google Scholar
Walenta, K. (1981) Seltene Eisenphosphate aus der Grube Clara. Mineralien-Magazin, 5, 422–424. (in German).Google Scholar
Walenta, K. (1990) Neue Mineralfunde von der Grube Clara (4. Folge). Lapis, 15(4), 36–39.Google Scholar
Walenta, K. (1992) Die Mineralien des Schwarzwaldes. Chr. Weise Verlag, Munich, Germany, 336 pp. (in German).Google Scholar
Walenta, K. (1995) Neue Mineralfunde von der Grube Clara. 6. Folge, 1. Teil. Lapis, 20(5), 33–38 (in German).Google Scholar
Walenta, K. and Binder, W. (1980) Kidwellit und Dufrenit aus den Mines de Montmins bei Echassiéres (franzö sisches Zentralma ssiv). Aufschluss, 31, 51–54. (in German).Google Scholar
Walenta, K. and Dunn, P.J. (1984) Phospho. brit, ein neues Eisenphosphat aus der Grube Clara im mittleren Schwarzwald (BRD). Chemie der Erde, 43, 11–16. (in German).Google Scholar
Witzke, T. and Giesler, T. (1997) Neufunde aus Sachsen (VI): Churchit-(Y), Cyrilovit, Faustit, Kidwellit, Meurigit und Nickelhexahydrit aus der Lausitz. Lapis, 22(9), 36–38; 58 (in German).Google Scholar