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Crystal-chemical aspects of the roméite group, A2Sb2O6Y, of the pyrochlore supergroup

Published online by Cambridge University Press:  26 January 2018

Ferdinando Bosi ,
Andrew G. Christy  and
Ulf Hålenius
Ferdinando Bosi*
Affiliation:
Dipartimento di Scienze della Terra, Sapienza Università di Roma, Piazzale A. , Moro 5, I-00185 Rome, Italy CNR-IGG Istituto di Geoscienze e Georisorse, Sede di Roma, Piazzale A. Moro, 5, I-00185 Rome, Italy
Andrew G. Christy
Affiliation:
Department of Applied Mathematics, Research School of Physics and Engineering, Australian National University, Canberra, ACT 2601, Australia
Ulf Hålenius
Affiliation:
Department of Geosciences, Swedish Museum of Natural History, Box 50007, SE-10405 Stockholm, Sweden
*
* E-mail: [email protected]
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Abstract

Four specimens of the roméite-group minerals oxyplumboroméite and fluorcalcioroméite from the Långban Mn-Fe deposit in Central Sweden were structurally and chemically characterized by single-crystal X-ray diffraction, electron microprobe analysis and infrared spectroscopy. The data obtained and those on additional roméite samples from literature show that the main structural variations within the roméite group are related to variations in the content of Pb2+, which is incorporated into the roméite structure via the substitution Pb2+→A2+ where A2+ = Ca, Mn and Sr. Additionally, the cation occupancy at the six-fold coordinated B site, which is associated with the heterovalent substitution BFe3+ + Y☐→BSb5++YO2-, can strongly affect structural parameters.

Chemical formulae of the roméite minerals group are discussed. According to crystal-chemical information, the species associated with the name ‘kenoplumboroméite’, hydroxycalcioroméite and fluorcalcioroméite most closely approximate end-member compositions Pb2(SbFe3+)O6☐, Ca2(Sb5+Ti) O6(OH) and (CaNa)Sb2O6F, respectively. However, in accord with pyrochlore nomenclature rules, their names correspond to multiple end-members and are best described by the general formulae: (Pb,#)2(Sb,#)2O6☐, (Ca,#)2(Sb,#)2O6(OH) and (Ca,#)Sb2(O,#)6F, where ‘#’ indicates an unspecified charge-balancing chemical substituent, including vacancies.

Keywords

oxyplumboroméitefluorcalcioroméiteroméite grouppyrochlore supergroupcrystal structure
Type
Research Article
Information
Mineralogical Magazine , Volume 81 , Issue 6 , December 2017 , pp. 1287 - 1302
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2017

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Footnotes

†

Present address: Geosciences, Queensland Museum, 122 Gerler Road, Hendra, Q1d 4011, Australia; School of Earth and Environmental Sciences, University of Queensland, St Lucia, Q1d 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. (2013) Hydroxycalciomicrolite, IMA 2013-073. CNMNC Newsletter No. 18, December 2013, page 3252; Mineralogical Magazine, 77, 3249–3258.Google Scholar
Atencio, D. (2016) Parabariomicrolite discredited as identical to hydrokenomicrolite-3R. Mineralogical Magazine, 80, 923–924.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, 673–698.CrossRefGoogle Scholar
Atencio, D., Ciriotti, M.E. and Andrade, M.B. (2013) Fluorcalcioroméite, (Ca,Na)2Sb5þ 2 (O,OH)6F, a new roméite-group mineral from Starlera mine, Ferrera, Grischun, Switzerland: description and crystal structure. Mineralogical Magazine, 77, 467–473.CrossRefGoogle Scholar
Balić-Žunic, T. (2007) Use of three-dimensional parameters in the analysis of crystal structures under compression. Pp. 157–184 in: Pressure-Induced Phase Transition (Grzechnik, A., editor). Transworld Research Network, Trivandrum, Kerala, India.Google Scholar
Balić-Žunic, T. and Makovicky, E. (1998) New measure of distortion for coordination polyhedra. Acta Crystallographica, B54, 766–773.Google Scholar
Balić-Žunic, T. and Vickovic, I. (1996) IVTON – program for the calculation of geometrical aspects of crystal structures and some crystal chemical applications. Journal of Applied Crystallography, 29, 305–306.CrossRefGoogle Scholar
Biagioni, C., Orlandi, P., Nestola, F. and Bianchin, S. (2013) Oxycalcioroméite, Ca2Sb2O6O, from Buca della Vena mine, Apuan Alps, Tuscany, Italy: a new member of the pyrochlore supergroup. Mineralogical Magazine, 77, 3027–3037.CrossRefGoogle Scholar
Brugger, J., Gieré, R., Graeser, S. and Meisser, N. (1997) The crystal chemistry of roméite. Contributions to Mineralogy and Petrology, 127, 136–146.CrossRefGoogle Scholar
Brown, I.D. and Shannon, R.D. (1973) Empirical bondstrength-bond-length curves for oxide. Acta Crystallographica, A29, 266–282.CrossRefGoogle Scholar
Christy, A.G. and Atencio, D. (2013) Clarification of status of species in the pyrochlore supergroup. Mineralogical Magazine, 77, 13–20.CrossRefGoogle Scholar
Christy, A.G. and Gatedal, K. (2005) Extremely Pb-rich rock-forming silicates including a beryllian scapolite and associated minerals in a skarn from Långban, Värmland, Sweden. Mineralogical Magazine, 69, 995–1018.CrossRefGoogle 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, 567–574.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, 235–255.CrossRefGoogle Scholar
Grew, E.S., Locock, A.J. Mills, S.J., Galuskina, I.O., Galuskin, E.V. and Hålenius, U. (2013) Nomenclature of the garnet supergroup. American Mineralogist, 98, 785–811.CrossRefGoogle Scholar
Hålenius, U. and Bosi, F. (2013) Oxyplumboroméite, Pb2Sb2O7, a new mineral species of the pyrochlore supergroup. Mineralogical Magazine, 77, 2931–2940.CrossRefGoogle Scholar
Hawthorne, F.C. (2002) The use of end-member chargearrangements in defining new mineral species and heterovalent substitutions in complex minerals. The Canadian Mineralogist, 40, 699–710.CrossRefGoogle Scholar
Libowitzky, E. and Rossman, G.R. (1997) An IR absorption calibration for water in minerals. American Mineralogist, 82, 1111–1115.CrossRefGoogle Scholar
Mason, B. and Vitaliano, C.J. (1953) The mineralogy of the antimony oxides and antimonates. Mineralogical Magazine, 30, 100–112.CrossRefGoogle Scholar
Matsubara, S., Kato, A.A., Shimizu, M., Sekiuchi, K. and Suzuki, Y. (1996) Romeite from Gozaisho mine, Iwaki, Japan. Mineralogical Journal, 18, 155–160.CrossRefGoogle Scholar
Mills, S.J., Christy, A.G., Rumsey, M.S. and Spratt, J. (2016) The crystal chemistry of elsmoreite from the Hemerdon (Drakelands) mine, UK: hydrokenoelsmoreite- 3C and hydrokenoelsmoreite-6R. Mineralogical Magazine, 80, 1195–1203.CrossRefGoogle Scholar
Pouchou, J.L. and Pichoir, F. (1991) Quantitative analysis of homogeneous or stratified microvolumes applying the model ‘PAP.’ Pp. 31–75 in: Electron Probe Quantitation (Heinrich, K.F.J. and Newbury, D.E., editors). Plenum Press, New York.CrossRefGoogle Scholar
Rouse, R.C., Dunn, P.J., Peacor, D.R. and Wang, L. (1998) Structural studies of the natural antimonian pyrochlores. I. Mixed valency, cation site splitting, and symmetry reduction in lewisite. Journal of Solid State Chemistry, 141, 562–569.CrossRefGoogle 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. (1996) SADABS. Program for Empirical Absorption Correction. University of Göttingen, Germany.Google Scholar
Sheldrick, G.M. (2013) SHELXL2013. University of Göttingen, Germany.Google Scholar
Williams, P.A., Leverett, P., Sharpe, J.L., Colchester, D.M. and Rankin, J. (2005) Elsmoreite, cubicWO3·0.5H2O, a new mineral species from Elsmore, New South Wales, Australia. The Canadian Mineralogist, 43, 1061–1064.CrossRefGoogle Scholar
Zubkova, N.V., Pushcharovksy, D.Yu., Atencio, D., Arakcheeva, A.V. and Matioli, P.A. (2000) The crystal structure of lewisite, (Ca,Sb3+,Fe3+,Al,Na, Mn,□)2(Sb5+,Ti)2O6(OH). Journal of Alloys and Compounds, 296, 75–79.CrossRefGoogle Scholar