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Hydroniumpharmacosiderite, a new member of the pharmacosiderite supergroup from Cornwall, UK: structure and description

Published online by Cambridge University Press:  05 July 2018

S. J. Mills ,
A. R. Kampf ,
P. A. Williams ,
P. Leverett ,
G. Poirier ,
M. Raudsepp  and
C. A. Francis
S. J. Mills*
Affiliation:
Department of Earth and Ocean Sciences, University of British Columbia, Vancouver BC, Canada V6T 1Z4
A. R. Kampf
Affiliation:
Mineral Sciences Department, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA
P. A. Williams
Affiliation:
School of Natural Sciences, University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797, Australia
P. Leverett
Affiliation:
School of Natural Sciences, University of Western Sydney, Locked Bag 1797, Penrith South DC, NSW 1797, Australia
G. Poirier
Affiliation:
Mineral Sciences Division, Canadian Museum of Nature, PO Box 3443, Station D, Ottawa, Ontario, Canada K1P 6P4
M. Raudsepp
Affiliation:
Department of Earth and Ocean Sciences, University of British Columbia, Vancouver BC, Canada V6T 1Z4
C. A. Francis
Affiliation:
Harvard Mineralogical Museum, 24 Oxford Street, Cambridge, Massachusetts 02138, USA
*
*E-mail: [email protected]
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Abstract

Hydroniumpharmacosiderite, ideally (H3O)Fe4(AsO4)3(OH)4·4H2O, is a new mineral from Cornwall, UK, probably from the St. Day group of mines. It occurs as a single yellowish green, slightly elongated cube, measuring 0.17 mm ×0.14 mm ×0.14 mm. The mineral is transparent with a vitreous lustre. It is brittle with a cleavage on {001}, has an irregular fracture, a white streak and a Mohs hardness of 2–3 (determined on H3O-exchanged pharmacosiderite). Hydroniumpharmacosiderite has a calculated density of 2.559 g cm–3 for the empirical formula. The empirical formula, based upon 20.5 oxygen atoms, is: [(H3O)0.50K0.48Na0.06]1.04(Fe3.79Al0.22)4.01[(As2.73P0.15)2.88O12](OH)4·4H2.14O. The five strongest lines in the X-ray powder diffraction pattern are [dobs(Å),Iobs,(hkl)]: 8.050,100,(001); 3.265,35,(112); 2.412,30,(113); 2.830,23,(202); 4.628,22,(111). Hydroniumpharmacosiderite is cubic, space group with a = 7.9587(2) Å, V = 504.11(2) Å3 and Z = 1. The crystal structure was solved by direct methods and refined to R1 = 0.0481 for 520 reflections with I > 2σ(I). The structure is consistent with determinations for H3O-exhchanged pharmacosiderite and the general pharmacosiderite structure type.

Keywords

hydroniumpharmacosideritecrystal structureCornwallnew mineralhydroniumpharmacosideriteUK
Type
Research Article
Information
Mineralogical Magazine , Volume 74 , Issue 5 , October 2010 , pp. 863 - 869
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2010

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References

Behrens, E.A., Poojary, D.M. and Clearfield, A. (1998) Syntheses, X-ray powder structures, and preliminary ion-exchange properties of germanium-substituted titanosilicate pharmacosiderites: HM3(AO)4(BO4)34H2O (M = K, Rb, Cs; A = Ti, Ge; B = Si, Ge). Chemistry of Materials, 10, 959–967.CrossRefGoogle Scholar
Bruker, (2003) SAINT, SADABS and SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA.Google Scholar
Buerger, M.J., Dollase, W.A. and Garaycochea-Wittke, I. (1967) The structure and composition of the mineral pharmacosiderite. Zeitsschrift für Kristallogrphie, 125, 92–108.CrossRefGoogle Scholar
Dadachov, M.S. and Harrison, W.T.A. (1997) Synthesis and crystal structure of Na4[(TiO)4(SiO4)3].6H2O, a rhombohedrally distorted sodium titanium silicate pharmacosiderite analogue. Journal of Solid State Sciences, 134, 409–415.CrossRefGoogle Scholar
Embrey, P.G. and Symes, R.F. (1987) Minerals of Cornwall and Devon. Natural History Museum, London.Google Scholar
Harrison, W.T.A, Gier, T.E. and Stucky, G.D. (1995) Single-crystal structure of Cs3HTi4O4(SiO4)3.4H2O, a titanosilicate pharmacosiderite analog. Zeolites, 15, 408–412.CrossRefGoogle Scholar
Hartley, E. (1899) Communications from the Oxford Mineralogical Laboratory. On the constitution of the natural arsenates and phosphates. Mineralogical Magazine, 12, 152–158.CrossRefGoogle 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 patterns. Journal of Applied Crystallography, 29, 301–303.CrossRefGoogle Scholar
Laugier, I. and Bochu, B. (2004) Chekcell: Graphical powder indexing cell and space group assignment software, http://www.ccpl4.ac.uk/tutorial/lmgp/ Google Scholar
Mills, S.J., Hager, S.L., Leverett, P., Williams, P.A. and Raudsepp, M. (2010) The structure of H3O+-exchanged pharmacosiderite. Mineralogical Magazine, 74, 487–492.CrossRefGoogle Scholar
Mills, S.J., Raudsepp, M., Kampf, A.R., Hager, S.L., Leverett, P., Williams, P.A., Hibbs, D.E. and Birch, W.D. (2010) The crystal chemistry of natropharma-cosiderite-C, bariopharmacosiderite-C and bario-pharmacosiderite-Q. The Canadian Mineralogist (submitted).Google Scholar
Mutter, G., Eysel, W., Greis, O. and Schmetzer, K. (1984) Crystal chemistry of natural and ion-exchanged pharmacosiderites. Neues Jahrbuch für Mineralogie, Monatshefte, 183–192.Google Scholar
Peacor, D.R. and Dunn, P.J. (1985) Sodium-pharmaco-siderite, a new analog of pharmacosiderite from Australia and new occurrences of barium-pharma-cosiderite. Mineralogical Record, 16, 121–124.Google Scholar
Phillips, W. (1811) A description of the Red Oxyd of Copper, the production of Cornwall, and the varieties of its crystal, and observations of the Lodes which principally produced it: and on the crystallization of the arseniated iron. Transactions of the Geological Society of London, 1, 23–37.CrossRefGoogle Scholar
Rumsey, M.S., Mills, S.J. and Spratt, J. (2010) Natropharmacoalumite, NaAl4[(OH)4(AsO4)3].4H2O, a new mineral of the pharmacosiderite supergroup and the renaming of aluminopharmaco-siderite to pharmacoalumite. Mineralogical Magazine, 74, 929–936.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica, A64, 112–122.CrossRefGoogle Scholar
Zemann, J. (1947) Über die Struktur des Pharmakosiderits. Experientia, 3, 452.CrossRefGoogle Scholar
Zemann, J. (1948) Formel und Struktur des Pharmakosiderits. Tschermaks Mineralogische und Petrographische Mitteilungen, 1, 1–13.CrossRefGoogle Scholar