Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-14T11:13:51.380Z Has data issue: false hasContentIssue false
  • English
  • Français

Nordgauite, MnAl2(PO4)2(F,OH)2·5H2O, a new mineral from the Hagendorf-Süd pegmatite, Bavaria, Germany: description and crystal structure

Published online by Cambridge University Press:  05 July 2018

W. D. Birch ,
I. E. Grey ,
S. J. Mills ,
A. Pring ,
C. Bougerol ,
A. Ribaldi-Tunnicliffe ,
N. C. Wilson  and
E. Keck
W. D. Birch*
Affiliation:
Geosciences, Museum Victoria, GPO Box 666, Melbourne 3001, Victoria, Australia
I. E. Grey
Affiliation:
CSIRO Process Science and Engineering, PO Box 312, Clayton, 3169, Victoria, Australia
S. J. Mills
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA
A. Pring
Affiliation:
Mineralogy Department, South Australian Museum, North Terrace, Adelaide, South Australia 5000
C. Bougerol
Affiliation:
CEA-CNRS-UJF group ‘Nanophysique et Semiconducteurs’, Institut Néel, CNRS-Université Joseph Fourier, 38042 Grenoble, France
A. Ribaldi-Tunnicliffe
Affiliation:
Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
N. C. Wilson
Affiliation:
CSIRO Process Science and Engineering, PO Box 312, Clayton, 3169, Victoria, Australia
E. Keck
Affiliation:
Algunderweg 3, 92694 Etzenricht, Germany
*
*E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Nordgauite, MnAl2(PO4)2(F,OH)2·5H2O, is a new secondary phosphate from the Hagendorf-Süd pegmatite, Bavaria, Germany. It occurs as white to off-white compact waxy nodules and soft fibrous aggregates a few millimetres across in altered zwieselite—triplite. Individual crystals are tabular prismatic, up to 200 μ long and 10 μ wide. Associated minerals include fluorapatite, sphalerite, uraninite, a columbite—tantalite phase, metastrengite, several unnamed members of the whiteite—jahnsite family, and a new analogue of kingsmountite. The fine-grained nature of nordgauite meant that only limited physical and optical properties could be obtained; streak is white; fracture, cleavage and twinning cannot be discerned. Dmeas. and Dcaic. are 2.35 and 2.46 g cm–3, respectively; the average RI is n = 1.57; the Gladstone-Dale compatibility is —0.050 (good). Electron microprobe analysis gives (wt.%): CaO 0.96. MgO 0.12, MnO 14.29, FeO 0.60, ZnO 0.24, A12O3 22.84, P2O5 31.62, F 5.13 and H2O 22.86 (by CHNX less F=O 2.16, total 96.50. The corresponding empirical formula is (Mn0.90Ca0.08Fe0.04Zn0.01Mg0.01)-Σi.04Ai2.0i(PO4)2[F1.21,(OH)0.90]Σ2.11·5.25H2O. Nordgauite is triclinic, space group P1̄, with the unit-cell parameters: a = 9.920(4), b = 9.933(3), c = 6.087(2) Å, α = 92.19(3), β = 100.04(3), γ = 97.61(3)°, V = 584.2(9) Å3 and Z = 2. The strongest lines in the XRD powder pattern are [d in Å (I) (hkl)] 9.806 (100)(010), 7.432 (40)(l1̄0), 4.119 (20)(210), 2.951 (16)(031), 4.596 (12)(21̄O), 3.225 (12)(220) and 3.215 (12)(121). The structure of nordgauite was solved using synchrotron XRD data collected on a 60 μm × 3 μm × 4 μm needle and refined to R1 = 0.0427 for 2374 observed reflections with F > 4σ(F). Although nordgauite shows stoichiometric similarities to mangangordonite and kastningite, its structure is more closely related to those of vauxite and montgomeryite in containing zig-zag strings of corner-connected Al-centred octahedra along [011], where the shared corners are alternately in cis and trans configuration. These chains link through corner-sharing with PO4 tetrahedra along [001] to form (100) slabs that are interconnected via edge-shared dimers of MnO6 polyhedra and other PO4 tetrahedra.

Keywords

nordgauitenew mineralHagendorf-Süd pegmatiteGermanyphosphatecrystal structure
Type
Research Article
Information
Mineralogical Magazine , Volume 75 , Issue 2 , April 2011 , pp. 269 - 278
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2011

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

Altomare, A., Cascarano, G., Giacovazzo, C. and Guagliardi, A. (1993) Completion and refinement of crystal structures with SIR92. Journal of Applied Crystallography, 26, 343-350.CrossRefGoogle Scholar
Baur, W.H. and Rao, B.R. (1968) The crystal structure and the chemical composition of vauxite. American Mineralogist, 53, 1025-1028.Google Scholar
Farrugia, L.J. (1999) WinGX suite for small-molecule single-crystal crystallography. Journal of Applied Crystallography, 32, 837-838.CrossRefGoogle Scholar
Grey, I.E., Mumme, W.G., Neville, S.M., Wilson, N.C. and Birch, W.D. (2010) Jahnsite-whiteite solid solutions and associated minerals in the phosphate pegmatite at Hagendorf-Sü d, Bavaria, Germany. Mineralogical Magazine, 74, 969-978.CrossRefGoogle Scholar
Keck, E. (1983) Phosphatmineralien und deren Auftreten in verschiedenen Teufen im Pegmatite von Hagendorf-Süd. Aufschluss, 34, 307-316.Google Scholar
Laugier, J. and Bochu, B. (2004) Chekcell: Graphical powder indexing cell and space group assignment software, http://www.ccp14.ac.uk/tutorial/lmgp/. Google Scholar
Leavens, P.B. and Rheingold, A.L. (1988) Crystal structures of gordonite, MgAl2(PO4)2(OH)2 (H2O)6·2H2O, and its Mn analogue. Neues Jahrbuch für Mineralogie Monatshefte, 1988, 265-270.Google Scholar
Leavens, P.B., White, J.S. Jr., Robinson, G.W. and Nelen, J.A. (1991) Mangangordonite, a new phosphate mineral from Kings Mountain, North Carolina and Newry, Maine, USA. Neues Jahrbuch für Mineralogie Monatshefte, 1991, 169-176.Google Scholar
Libowitzky, E. (1999) Correlation of O–H stretching frequencies and O–H···O hydrogen bond lengths in minerals. Monatshefte für Chemie, 130, 1047-1059.CrossRefGoogle Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship: Part IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441-450.Google Scholar
Moore, P.B. and Araki, T. (1974) Montgomeryite, Ca4Mg(H2O)12[Al4(OH)4(PO4)6]: Its crystal structure and relation to vauxite, Fe2+ 2 (H2O)4[Al4(OH)4 (H2O)4(PO4)4]·4H2O. American Mineralogist, 59, 843-850.Google Scholar
Mücke, A. (1981) The paragenesis of the phosphate minerals of the Hagendorf pegmatite – a general view. Chemie der Erde, 40, 217-234.Google Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112-122.CrossRefGoogle Scholar
Schlüter, J., Klaska, K.-H., Friese, K. and Adiwidjaja, G. (1999) Kastningite, (Mn,Fe,Mg)Al2(PO4)2 (OH)2.8H2O, a new phosphate mineral from Waidhaus, Bavaria, Germany. Neues Jahrbuch für Mineralogie Monatshefte, 1999, 40-48.Google Scholar
Strunz, H., Tennyson, C. and Mücke, A. (1976) Mineralien von Hagendorf (Ostbayern). Aufschluss, 27, 329-340.Google Scholar
Visser, J.W. (1969) A fully automated program for finding the unit cell from powder data. Journal of Applied Crystallography, 2, 89.CrossRefGoogle Scholar
Supplementary material: File

Birch et al. supplementary material

Anisotropic displacement factors and Calculated structure factors

Download Birch et al. supplementary material(File)
File 141.7 KB