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Magnesiobermanite, MgMn3+2(PO4)2(OH)2⋅4H2O, the Mg analogue of bermanite: Description and crystal structure

Published online by Cambridge University Press:  13 December 2021

Peter Elliott Open the ORCID record for Peter Elliott [Opens in a new window]
Peter Elliott*
Affiliation:
Department of Earth Sciences, School of Physical Sciences, The University of Adelaide, Adelaide, South Australia 5005, Australia South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
*
*Author for correspondence: Peter Elliott, Email: [email protected]
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Abstract

Magnesiobermanite, MgMn3+2(PO4)2(OH)2⋅4H2O, is a new secondary phosphate mineral and the Mg analogue of bermanite found in a granitic pegmatite at the White Rock No.2 quarry situated in the Bimbowrie Conservation Park, South Australia, Australia. Magnesiobermanite occurs as aggregates of twinned, bladed to tabular crystals, up to 1.2 mm across. Individual crystals are up to 0.3 mm in length. The crystals are orange–red to brownish red, with a vitreous lustre and a salmon-pink streak. The mineral is brittle with a conchoidal fracture and a good cleavage on {100}. The mineral is biaxial (–), with α = 1.690(2), β = 1.719(2) and γ = 1.734(2) (white light). The calculated 2V is 70.4°. Electron microprobe analyses provided: MgO 9.59, Mn2O3 27.41, Fe2O3 8.84, Al2O3 0.18, P2O5 33.27, H2O 20.94, total 100.23 wt.%. The empirical formula (based on 14 O atoms) is: Mg1.02(Mn3+1.49Fe3+0.47Al0.02)1.98(PO4)2.01(OH)1.95⋅4.01H2O. Magnesiobermanite is monoclinic, space group P21, with the unit-cell parameters: a = 5.4215(11), b = 19.072(4), c = 5.3889(11) Å, β = 110.21(3)°, V = 522.89(18) Å3 and Z = 2. The crystal structure was refined to an R1 index of 2.43% based on for 3222 observed reflections with Fo > 4σ(Fo). Magnesiobermanite is isostructural with bermanite, Mn2+Mn3+2(PO4)2(OH)2⋅4H2O, from which it derives its name. The structure is based upon a sheet of the form [(M(OH)2(PO4)2] in the (010) plane. Sheets are linked in the b direction by [M3(H2O)4O2] octahedra and by hydrogen bonds.

Keywords

magnesiobermanitenew mineral speciesmagnesium manganese phosphatepegmatitecrystal structureWhite Rock No.2 quarryAustralia
Type
Article
Information
Mineralogical Magazine , Volume 86 , Issue 1 , February 2022 , pp. 127 - 133
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press on behalf of The Mineralogical Society of Great Britain and Ireland

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Footnotes

Associate Editor: David Hibbs

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
Bruker (2001) SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.Google Scholar
Burns, P.C., Cooper, M. and Hawthorne, F.C. (1994) Jahn-Teller distorted Mn3+O6 octahedra in fredrikssonite, the forth polymorph of Mg2Mn3+(BO3)2. The Canadian Mineralogist, 32, 397–403.Google Scholar
Callegari, A.M., Boiocchi, M., Ciriotti, M.E. and Balestra, C. (2012) Coralloite, Mn2+Mn3+2(AsO4)2(OH)2⋅4H2O, a new mixed valence Mn hydrate arsenate: Crystal structure and relationships with bermanite and whitmoreite mineral groups. American Mineralogist, 97, 727–734.CrossRefGoogle Scholar
Cooper, M.A., Hawthorne, F.C. and Černý, P. (2009) The crystal structure of ercitite, Na2(H2O)4[Mn3+2(OH)2(PO4)2], and its relation to bermanite, Mn2+(H2O)4[Mn3+2(OH)2(PO4)2]. The Canadian Mineralogist, 47, 173–180.CrossRefGoogle Scholar
Elliott, P. (2019) Magnesiobermanite, IMA 2018-115. CNMNC Newsletter No. 47, February 2019, page 144. Mineralogical Magazine, 83, 143–147.Google Scholar
Fransolet, A.M., Cooper, M.A., Cerný, P., Hawthorne, F.C., Chapman, R. and Grice, J.D. (2000) The Tanco pegmatite at Bernic Lake, southeastern Manitoba. XV. Ercitite, Na,Mn3+PO4(OH)(H2O)2, a new phosphate mineral species. The Canadian Mineralogist, 38, 893–898.CrossRefGoogle Scholar
Gagné, O.C. and Hawthorne, F.C. (2015) Comprehensive derivation of bond-valence parameters for ion pairs involving oxygen. Acta Crystallographica, B71, 562–578.Google Scholar
Holland, T.J.B. and Redfern, S.A.T. (1997) Unit cell refinement from powder diffraction data; the use of regression diagnostics. Mineralogical Magazine, 61, 65–77.CrossRefGoogle Scholar
Hurlbut, C.S. Jr. (1936) A new phosphate, bermanite, occurring with triplite in Arizona. American Mineralogist, 21, 656–661.Google Scholar
Kabsch, W. (2010) XDS. Acta Crystallographica, D66, 125–132.Google Scholar
Kampf, A.R. and Moore, P.B. (1976) The crystal structure of bermanite, a hydrated manganese phosphate. American Mineralogist, 61, 1241–1248.Google Scholar
Kraus, W. and Nolze, G. (1996) POWDER CELL – a program for the representation and manipulation of crystal structures and calculation of the resulting X-ray powder pattern. Journal of Applied Crystallography, 29, 301–303.CrossRefGoogle Scholar
Leavens, P.B. (1967) Reexamination of bermanite, American Mineralogist, 52, 1060–1066.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
Lottermoser, B.G., and Lu, J. (1997) Petrogenesis of rare-element pegmatites in the Olary Block, South Australia, part 1. Mineralogy and chemical evolution. Mineralogy and Petrology, 59, 1–19.CrossRefGoogle Scholar
Olliver, J.G. and Steveson, B.G. (1982) Pegmatites in the Olary Province. A review of feldspar and beryl mining north of Olary and the results of reconnaissance sampling of feldspar. South Australia, Department of Mines and Energy, Report Book, 81/74.Google Scholar
Pouchou, J.L. and Pichoir, F. (1985) “PAP” (πρZ) procedure for improved quantitative microanalysis. Pp. 104–106 in: Microbeam Analysis (Armstrong, J.T., editors). San Francisco Press, California.Google Scholar
Shannon, R.D. (1976) Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica, A32, 751–767.CrossRefGoogle Scholar
Sheldrick, G.M. (2015a) SHELXT – Integrated space-group and crystal-structure determination. Acta Crystallographica, A71, 3–8.Google Scholar
Sheldrick, G.M. (2015b) Crystal structure refinement with SHELXL. Acta Crystallographica, C71, 3–8.Google Scholar
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