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Whiteite-(CaMnMn), CaMnMn2Al2[PO4]4(OH)2·8H2O, a new mineral from the Hagendorf-Süd granitic pegmatite, Germany

Published online by Cambridge University Press:  05 July 2018

V. N. Yakovenchuk
Affiliation:
Nanomaterials Research Centre, Kola Science Centre of the Russian Academy of Sciences, 14 Fersman Street, Apatity 184200, Murmansk Region, Russia
E. Keck
Affiliation:
Algunder Weg 3, B-92694 Etzenricht, Germany
S. V. Krivovichev
Affiliation:
Nanomaterials Research Centre, Kola Science Centre of the Russian Academy of Sciences, 14 Fersman Street, Apatity 184200, Murmansk Region, Russia Department of Crystallography, St Petersburg State University, University Emb. 7/9, St Petersburg 199034, Russia
Y. A. Pakhomovsky
Affiliation:
Nanomaterials Research Centre, Kola Science Centre of the Russian Academy of Sciences, 14 Fersman Street, Apatity 184200, Murmansk Region, Russia
E. A. Selivanova
Affiliation:
Nanomaterials Research Centre, Kola Science Centre of the Russian Academy of Sciences, 14 Fersman Street, Apatity 184200, Murmansk Region, Russia
J. A. Mikhailova
Affiliation:
Nanomaterials Research Centre, Kola Science Centre of the Russian Academy of Sciences, 14 Fersman Street, Apatity 184200, Murmansk Region, Russia
A. P. Chernyatieva
Affiliation:
Department of Crystallography, St Petersburg State University, University Emb. 7/9, St Petersburg 199034, Russia
G. Yu. Ivanyuk*
Affiliation:
Nanomaterials Research Centre, Kola Science Centre of the Russian Academy of Sciences, 14 Fersman Street, Apatity 184200, Murmansk Region, Russia
*

Abstract

Whiteite-(CaMnMn), CaMnMn2Al2[PO4]4(OH)2·8H2O, is a new hydrous phosphate of Ca, Mn and Al, which is closely related to both jahnsite-(CaMnMn) and the minerals of the whiteite group. It is monoclinic, P2/a, with a = 15.02(2), b = 6.95(1), c =10.13(3) Å, β = 111.6(1)°, V = 983.3(6) Å3, Z = 2 (from powder diffraction data) or a = 15.020(5), b = 6.959(2), c = 10.237(3) Å, β = 111.740(4)°,V = 984.3(5) Å3, Z = 2 (from single-crystal diffraction data). The mineral was found in the Hagendorf Süd granitic pegmatite (Germany) as small (up to 0.5 mm in size) crystals elongated on a and tabular on {010}. The crystals are either simply or polysyntheticallytwinned on {001}. They crystallize on the walls of voids within altered zwieselite crystals or form coronas (up to 1 mm in diameter) around cubic crystals of uraninite. The mineral is transparent, colourless to pale yellow (depending on Al–Fe3+ substitution), with a vitreouslustre and a white streak. The cleavage is perfect on {001}, the fracture is stepped and the Mohs hardness is 3½. In transmitted light, the mineral is colourless; dispersion was not observed. Whiteite-(CaMnMn) is biaxial (+), α = 1.589(2), β = 1.592(2), γ = 1.601(2)(589 nm), 2Vmeas = 60(10)°, 2Vcalc = 60.3°. The optical orientation is X = b, Z^a = 5°. The calculated and measured densities are D calc = 2.768 and D meas = 2.70(3) g cm–3, respectively.The mean chemical composition determined by electron microprobe is Na2O 0.53, MgO 0.88, Al2O3 11.66, P2O5 34.58, CaO 4.29, MnO 17.32, FeO 8.32, ZnO 2.60 wt.%, with H2O 19.50 wt.% (determined by the Penfield method), giving atotal of 99.68 wt.%. The empirical formula calculated on the basis of four phosphorus atoms per formula unit, with ferric iron calculated to maintain charge balance, is (Ca0.63Zn0.26Na0.14)Σ1.03(Mn0.60Fe0.40 2+)Σ1.00(Mn1.40Fe0.37 2+Mg0.18Fe0.06 3+)Σ2.01(Al1.88Fe0.12 3+)Σ2.00[PO4]4(OH)2·7.89H2O.The simplified formula is CaMnMn2Al2[PO4]4(OH)2·8H2O. The mineral is easily soluble in 10% HCl at room temperature. The strongest X-ray powder-diffraction lines [listed as d in Å (I) (hkl)]are as follows: 9.443(65)(001), 5.596(25)(011), 4.929(80)(210), 4.719(47)(002), 3.494(46)(400), 2.7958(100)(022). The crystal structure of whiteite-(CaMnMn) was refined for a single crystal twinned on (001) to R 1 = 0.068 on the basis of 5702 unique observed reflections. Itis similar to the structures of other members of the whiteite group. The mineral is named for the chemical composition, in accordance with whiteite-group nomenclature.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2016

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References

Birch, W.D., Grey, I.E., Mills, S.J., Pring, A., Bougerol, C., Ribaldi-Tunnicliffe, A., Wilson, N.C. and Keck, E. (2011) Nordgauite, MnAl2(PO4)2(F,OH)2·5H2O, a new mineral from the Hagendorf-Süd pegmatite, Bavaria, Germany: description and crystal structure. Mineralogical Magazine, 75, 269278.CrossRefGoogle Scholar
Bolte, M. (2004) TWINLAW and HKLF5: two programs for the handling of non-merohedral twins. Journal of Applied Crystallography, 37, 162165.CrossRefGoogle Scholar
Brese, N.E. and O’Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallographica, B47, 192197.CrossRefGoogle Scholar
Forster, A., Strunz, H. and Tennyson, Ch. (1967) Die Pegmatite des Oberpfälzer Waldes, insbesondere der Pegmatit von Hagendorf-Sü d. Aufschluss, 16, 137198.Google 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, 969978.CrossRefGoogle Scholar
Grice, J.D., Dunn, P.J. and Ramik, R.A. (1989) Whiteite-(CaMnMg), a new mineral species from the Tip Top pegmatite, Custer, South Dakota. The Canadian Mineralogist, 27, 699702.Google Scholar
Grice, J.D., Dunn, P.J. and Ramik, R.A. (1990) Jahnsite- (CaMnMn), a new member of the whiteite group from Mangualde, Beira, Portugal. American Mineralogist, 75, 401404.Google Scholar
Kampf, A.R., Steele, I.M. and Loomis, T.A. (2008) Jahnsite-(NaFeMg), a new mineral from the Tip Top mine, Custer County, South Dakota: description and crystal structure. American Mineralogist, 93, 940945.CrossRefGoogle Scholar
Mandarino, J.A. (1981) The Gladstone-Dale relationship. IV. The compatibility concept and its application. The Canadian Mineralogist, 19, 441450.Google Scholar
Moore, P.B. and Araki, T. (1974) Jahnsite, CaMnMg2(H2O)8Fe2(OH)2(PO4)4. A novel stereoisomerism of ligands about octahedral corner-chains. American Mineralogist, 59, 964973.Google Scholar
Moore, P.B. and Ito, J. (1978) I. Whiteite, a new species, and a proposed nomenclature for the jahnsite -whiteite complex series. II. New data on xanthoxenite. III. Salmonsite discredited. Mineralogical Magazine, 42, 309323.CrossRefGoogle Scholar
Mücke, A. (1981) The parageneses of the phosphate minerals of the Hagendorf pegmatite - a general view. Chemie der Erde, 40, 217234.Google Scholar
Mücke, A., Keck, E. and Haase, J. (1990) Die genetische Entwicklung des Pegmetits von Hagendorf-Sü d/ Oberpfalz. Aufschluss, 41, 3351.Google Scholar
Sandell, E.B. (1951) Micro determination of water by the Penfield method. Microchimica Acta, 38, 487491.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112122.CrossRefGoogle Scholar
Strunz, H. and Forster, A. (1975) Der Pegmatit von Hagendorf-Süd. Aufschluss, 26, 329339.Google Scholar
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