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Reaphookhillite, MgZn2(PO4)2⋅4H2O, the Mg analogue of parahopeite from Reaphook Hill, South Australia

Published online by Cambridge University Press:  18 February 2022

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]

Abstract

Reaphookhillite, ideally MgZn2(PO4)2⋅4H2O, is a new phosphate mineral from Reaphook Hill, Flinders Ranges, South Australia, Australia. Reaphookhillite occurs as colourless, bladed to thin tabular crystals to 0.6 mm across. Cleavage is perfect parallel to {010}. The mineral occur as overgrowths on parahopeite crystals and is associated with scholzite, leucophosphite and chalcophanite. The calculated density is 3.09 g/cm3 from the empirical formula. Reaphookhillite is optically biaxial (+), α = 1.583(3), β = 1.596(3), γ = 1.611(3) and 2Vcalc = 88.7°. Electron microprobe analyses gave ZnO 41.57, MgO 7.96, MnO 0.40, P2O5 33.72, H2O(calc) 16.92, total 100.57 wt.%. The empirical formula, based on 12 O apfu, is Mg0.83Zn2.16Mn2+0.02(PO4)2.01⋅3.97H2O. Reaphookhillite is triclinic, P${\bar 1}$, with the unit-cell parameters of a = 5.7588(12), b = 7.5341(15) c = 5.2786(11) Å, α = 93.44(3), β = 91.27(3), γ = 91.30(3)°, V = 228.49(8) Å3 and Z = 1. The strongest eight lines in the powder X-ray diffraction pattern are [dobs in Å (I) (hkl)] 7.577 (100) (010); 4.461 (24) (01${\bar 1}$); 4.461 (24) (01${\bar 1}$); 3.771 (14) (020); 3.158 (13) (02${\bar 1}$); 2.982 (32) (021); 2.880 (27) (200); 2.775 (14) (1${\bar 2}$1, 12${\bar 1}$); and 2.668 (13) (1${\bar 2}{\bar 1}$, 210). Reaphookhillite is isostructural with parahopeite, with Mg replacing Zn in the 6-coordinated site in the structure. The structure contains ZnO4 and PO4 tetrahedra which share corners to form a sheet in the (001) plane. Sheets are linked in the c direction by corner sharing MgO2(H2O)4 octahedra.

Type
Article
Copyright
Copyright © The Author(s), 2022. Published by Cambridge University Press on behalf of The Mineralogical Society of Great Britain and Ireland

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Footnotes

Associate Editor: Anthony R Kampf

This paper is part of a thematic set that honours the contributions of Peter Williams.

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
Cametti, G., Churakov, S. and Armbruster, T. (2017) Reinvestigation of the zemannite structure and its dehydration behavior: a single-crystal X-ray and atomistic simulation study. European Journal of Mineralogy, 29, 5361.CrossRefGoogle Scholar
Chao, G.Y. (1969) Refinement of the crystal structure of parahopeite, Zeitschrift für Kristallographie, 130, 261266.CrossRefGoogle Scholar
Elliott, P. (2019) Reaphookhillite, IMA 2018-128. CNMNC Newsletter No. 47, February 2019, page 146. Mineralogical Magazine, 83, 143147.Google Scholar
Farrugia, L.J. (1999) WinGX Suite for Single Crystal Small Molecule Crystallography. Journal of Applied Crystalography, 32, 837838.CrossRefGoogle Scholar
Ferraris, G. and Ivaldi, G. (1988) Bond valence vs. bond length in O···O hydrogen bonds. Acta Crystallographica, B44, 341344.CrossRefGoogle Scholar
Gagné, O.C. and Hawthorne, F.C. (2015) Comprehensive derivation of bond-valence parameters for ion pairs involving oxygen. Acta Crystallographica, B71, 562578.Google Scholar
Hawthorne, F.C., Cooper, M.A., Abdu, Y.A., Ball, N.A., Back, M.E. and Tait, K.T. (2012) Davidlloydite, ideally Zn3(AsO4)2(H2O)4, a new arsenate mineral from the Tsumeb mine, Otjikoto (Oshikoto) region, Namibia: description and crystal structure. Mineralogical Magazine, 7, 4557.CrossRefGoogle Scholar
Hill, R.J. (1975) The Crystals Structure of the Mineral Scholzite and a Study of the Crystal Chemistry of Zinc in Some Related Phosphate and Arsenate Minerals. PhD Thesis, The University of Adelaide, Australia.Google Scholar
Hill, R.J. (1977) The crystal structure of phosphophyllite. American Mineralogist, 62, 812817.Google Scholar
Hill, R.J. and Jones, J.B. (1976) The crystal structure of hopeite. American Mineralogist, 61, 987995.Google Scholar
Hill, R.J. and Milnes, A.R. (1974) Phosphate minerals from Reaphook Hill, Flinders Ranges, South Australia. Mineralogical Magazine, 39, 684695.CrossRefGoogle Scholar
Hill, R.J., Johnson, J.E. and Jones, J.B. (1973) Scholzite and other phosphate minerals from Reaphook Hill, South Australia. Neues Jahrbuch für Mineralogie Monatshefte, 18.CrossRefGoogle 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, 6577.CrossRefGoogle Scholar
Holtstam, D., Gatedal, K. Söderberg, K. and Norrestam, R. (2001) Rinmanite, Zn2Sb2Mg2Fe4O14(OH)2, a new mineral species with a nolanite-type structure from the Garpenberg Norra mine, Dalarna, Sweden. The Canadian Mineralogist, 39, 16751685.CrossRefGoogle Scholar
Johns, R.K. (1972) Base Metal Occurrences with Lower Cambrian Sediments of the Northern Flinders Ranges. South Australian Geological Survey, Report of Investigations, 37.Google Scholar
Johnson, J.E. (1978) Zinc phosphate minerals from Reaphook Hill, South Australia. Australian Mineralogist, 1, 6568.Google Scholar
Johnston, C.W. and Hill, R.J. (1978) Zinc phosphates at Reaphook Hill South Australia. Mineralogical Record, 9, 2024.Google Scholar
Kampf, A.R., Mills, S.J., Simmons, W.B., Nizamoff, J.W. and Whitmore, R.W. (2012) Falsterite, Ca2MgMn2+2(Fe2+0.5Fe3+0.5)4Zn4(PO4)8(OH)4(H2O)14, a new secondary phosphate mineral from the Palermo No. 1 pegmatite, North Groton, New Hampshire. American Mineralogist, 97, 496502.CrossRefGoogle Scholar
Kampf, A.R., Falster, A.U., Simmons, W.B. and Whitmore, R.W. (2013) Nizamoffite, Mn2+ Zn2(PO4)2(H2O)4, the Mn analogue of hopeite from the Palermo No. 1 pegmatite, North Groton, New Hampshire. American Mineralogist, 98, 18931898.CrossRefGoogle Scholar
Libowitzky, E. (1999) Correlation of O-H stretching frequencies and O-H⋅⋅⋅O hydrogen bond lengths in minerals. Monatshefte für Chemie, 130, 10471059.CrossRefGoogle Scholar
Mills, S.J., Grey, I.E., Kampf, A.R., Macrae, C.M., Smith, J.B., Davidson, C.J. and Glenn, A.M. (2016) Ferraioloite, a new secondary phosphate mineral from the Foote mine, USA. European Journal of Mineralogy, 28, 655661.CrossRefGoogle Scholar
Missen, O.P., Mills, S.J., Spratt, J., Birch, W.D. and Brugger, J. (2019) Crystal chemistry of zemannite-type structures: I. A re-examination of zemannite from Moctezuma, Mexico. European Journal of Mineralogy, 31, 519527.CrossRefGoogle Scholar
Neuhold, F., Kolitsch, U., Bernhardt, H.-J. and Lengauer, C.L. (2012) Arsenohopeite, a new zinc arsenate mineral from the Tsumeb mine, Namibia. Mineralogical Magazine, 76, 603612.CrossRefGoogle Scholar
Pouchou, J.L. and Pichoir, F. (1985) “PAP” φ(ρZ) procedure for improved quantitative microanalysis. Pp. 104–106 in: Microbeam Analysis (J.T. Armstrong, editor). San Francisco Press, California, USA.Google Scholar
Rieck, B., Giester, G., Lengauer, L.C., Chanmuang, C. and Topa, D. (2020) Stergiouite, CaZn2(AsO4)2⋅4H2O – a new mineral from the Lavrion Mining District, Greece. Mineralogy and Petrology, 14, 319327.CrossRefGoogle Scholar
Rigaku Oxford Diffraction (2015) CrysAlisPro Software system, version 1.171.38.43. Rigaku Corporation.Google Scholar
Robinson, K., Gibbs, G.V. and Ribbe, P.H. (1971) Quadratic elongation; a quantitative measure of distortion in coordination polyhedra. Science, 172, 567570.CrossRefGoogle ScholarPubMed
Sheldrick, G.M. (2015a) SHELXT - Integrated space-group and crystal-structure determination. Acta Crystallographica, A71, 38.Google Scholar
Sheldrick, G.M. (2015b) Crystal structure refinement with SHELXL. Acta Crystallographica, C71, 38.Google Scholar
Thomas, I.M. and Weller, M.T. (1992) Synthesis, structure and thermal properties of phosphophyllite, Zn2Fe(PO4)2⋅4H2O. Journal of Materials Chemistry, 2, 11231126.CrossRefGoogle Scholar
Yvon, K., Jeitschko, W., and Parthé, E. (1977) LAZY PULVERIX, a computer program, for calculating X-ray and neutron diffraction powder patterns. Journal of Applied Crystallography, 10, 7374.CrossRefGoogle Scholar
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