Hostname: page-component-586b7cd67f-dlnhk Total loading time: 0 Render date: 2024-11-21T16:47:46.089Z Has data issue: false hasContentIssue false

The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: hydrokenoelsmoreite-3C and hydrokenoelsmoreite-6R

Published online by Cambridge University Press:  02 January 2018

Stuart J. Mills*
Affiliation:
Geosciences, Museum Victoria, GPO Box 666, Melbourne, Victoria 3001, Australia
Andrew G. Christy
Affiliation:
Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601, Australia
Mike S. Rumsey
Affiliation:
Earth and Planetary Mineralogy Division, Department of Earth Sciences, Natural History Museum, Cromwell Road, London SW7 5BD, UK
John Spratt
Affiliation:
Core Research Laboratories, Facilities Department, Natural History Museum, Cromwell Road, London SW7 5BD, UK

Abstract

A crystallographic and chemical study of two 'elsmoreite' samples (previously described as 'ferritungstite') from the Hemerdon mine (now known as the Drakelands mine), Devon, United Kingdom has shown them to be two different polytypes of hydrokenoelsmoreite. Hydrokenoelsmoreite-3C(HKE-3C) crystallizes in space group , with the unit-cell parameter a = 10.3065(3) Å. Hydrokenoelsmoreite-6R (HKE-6R) crystallizes in space group , with the unit-cell parameters a = 7.2882(2) Å and c = 35.7056(14)Å. Chemical analyses showed that both polytypes have Na and Fe/Al substitution giving the formulae: (Na0.28Ca0.04K0.02(H2O)0.201.46)∑2.00(W1.47Fe3+0.32Al0.21As5+0.01)∑2.00[O4.79(OH)1.21]∑6.00·(H2O)(3C) and (Na0.24Ca0.04K0.03(H2O)0.631.06)∑2.00(W1.42Fe3+0.49Al0.08As5+0.01)∑2.00[O4.65(OH)1.35]∑6.00·(H2O)(6R). The doubling of the unit cell in the 6R phase is due to ordering of Na and ( ,H2O) in the A site; no long-range ordering is observed between W and Fe/Al in the B site.

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

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.)

Footnotes

Current address: Queensland Museum, 122 Gerler Road, Hendra, Queensland 4011, and School of Earth Sciences, University of Queensland, St Lucia, Queensland 4072, Australia

References

Andrade, M.B., Yang, H., Atencio, D., Downs, R.T., Chukanov, N.V., Lemée-Cailleau, M.-H., Persiano, A.I.C., Goeta, A.E. and Ellena, J. (2016) Hydroxycalciomicrolite, Ca1. 5Ta2O6(OH), a new member of the microlite group from Volta Grande pegmatite, Nazareno, Minas Gerais, Brazil. Mineralogical Magazine, 81, (in press) https://doi. org/10.1180/minmag.2016.080.11.Google Scholar
Atencio, D. (2016) Parabariomicrolite discredited as identical to hydrokenomicrolite-3R. Mineralogical Magazine, 80, 923924.CrossRefGoogle Scholar
Atencio, D., Andrade, M.B., Christy, A.G., Gieré, R. and Kartashov, P.M. (2010) The pyrochlore supergroup of minerals: nomenclature. The Canadian Mineralogist, 48, 673698.CrossRefGoogle Scholar
Birch, W.D., Grey, I.E., Mills, S.J., Bougerol, C., Pring, A. and Ansermet, S. (2007) Pittongite: a new secondary mineral from Pittong, Victoria, Australia. The Canadian Mineralogist, 45, 857—864.Google Scholar
Bruker (2003) SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.Google Scholar
Cameron, J. (1951) The geology of Hemerdon wolfram mine, Devon. Transactions of the Institute of Mining and Metallurgy, 61, 1—14.Google Scholar
Ercit, T.S. and Robinson, G.W. (1994) A refinement of the structure of ferritungstite from Kalzas Mountain, Yukon, and observations on the tungsten pyrochlores. The Canadian Mineralogist, 32, 567574.Google Scholar
Ercit, T.S., Hawthorne, F.C. and Černý, P. (1986) Parabariomicrolite, a new species and its structural relationship to the pyrochlore group. The Canadian Mineralogist, 24, 655—663.Google Scholar
Ercit, T.S.,Černý, P. and Hawthorne, F.C. (1993) Cesstibtantite - a geologic introduction to the inverse pyrochlores. Mineralogy and Petrology, 48, 235255.CrossRefGoogle Scholar
Grey, I.E., Birch, W.D., Bougerol, C. and Mills, S.J. (2006) Unit-cell intergrowth of pyrochlore and hexagonal tungsten bronze structures in secondary tungsten minerals. Journal of Solid State Chemistry, 179, 38603869.CrossRefGoogle Scholar
Grey, I.E., Mumme, W.G., Vanderah, T.A., Roth, R.S. and Bougerol, C. (2007) Chemical twinning of the pyrochlore structure in the system Bi2O3—Fe2O3—Nb2O5. Journal of Solid State Chemistry, 180, 158166.CrossRefGoogle Scholar
Grey, I.E., Mumme, W.G. and MacRae, C.M. (2013) Lead-bearing phyllotungstite from the Clara mine, Germany with an ordered pyrochlore-hexagonal tungsten bronze intergrowth structure. Mineralogical Magazine, 77, 5767.CrossRefGoogle Scholar
Günter, J.R., Amberg, M. and Schmalle, H. (1989) Direct synthesis and single crystal structure determination of cubic pyrochlore-type tungsten trioxide hemihydrate, WCy0.5H2O. Materials Research Bulletin, 24, 289292.CrossRefGoogle Scholar
Loopstra, B.O. and Goubitz, K. (1986) The structures of four caesium tellurates. Acta Crystallographica, C42, 520523.Google Scholar
Mills, S.J., Christy, A.G. and Kampf, A.R. (2016) A review of the structural architecture of tellurium oxycom-pounds. Mineralogical Magazine, 80, 415545.Google Scholar
Mumme, W.G., Grey, I.E., Birch, W.D., Pring, A., Bougerol, C. and Wilson, N.C. (2010) Coulsellite, CaNa3AlMg3F14, a rhombohedral pyrochlore with 1:3 ordering in both A and B sites, from the Cleveland Mine, Tasmania, Australia. American Mineralogist, 95, 736740.CrossRefGoogle Scholar
Sheldrick, G.M. (2008) A short history of SHELX. Acta Crystallographica,A64, 112—122.Google Scholar
Walenta, K. (1984) Phyllotungstit, ein neues sekundares Wolframmineral aus der Grube Clara im mittleren Schwarzwald. Neues Jahrbuch für Mineralogie, Monatshefe, 12, 529535.Google Scholar
Williams, P.A., Leverett, P., Sharpe, J.L. and Colchester, D.M. (2005) Elsmoreite, cubic WO3.0.5H2O, a new mineral species from Elsmore, New South Wales. The Canadian Mineralogist, 43, 1061—1064.CrossRefGoogle Scholar