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Unit-cell parameters for scapolite solid solutions and a discontinuity at Me75, ideally NaCa3[Al5Si7O24](CO3)

Published online by Cambridge University Press:  04 September 2013

Sytle M. Antao*
Affiliation:
Department of Geoscience, University of Calgary, Calgary, Alberta T2N 1N4, Canada
*
a)Author to whom correspondence should be addressed. Electronic mail: ntao@ucalgary.ca

Abstract

Twenty-seven scapolite samples from various localities and with compositions between Me6–93 were obtained using electron microprobe analysis (EMPA). Their unit-cell parameters were obtained using synchrotron high-resolution powder X-ray diffraction (HRPXRD) data and Rietveld structure refinements using space group P42/n. The EMPA data show the well-known discontinuity at Me75. In addition, the unit-cell parameters, especially c, show a discontinuity at Me75 (=five Al atoms per formula unit, apfu), ideally NaCa3[Al5Si7O24](CO3), where the scapolite solid solution is divided into two (Me% = [Ca/(Ca + Na + K)] × 100). A maximum c parameter value occurs at Me37.5 (=four Al apfu ideally), where complete Al–Si, Na–Ca, and Cl–CO3 order occurs. The unit-cell volume, V, varies smoothly with Me% and Al apfu across the series.

Type
Technical Articles
Copyright
Copyright © International Centre for Diffraction Data 2013 

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References

Antao, S. M. and Hassan, I. (2002). “Thermal behavior of scapolite Me 79.6 and Me 33.3,Can. Mineral. 40, 13951401.CrossRefGoogle Scholar
Antao, S. M. and Hassan, I. (2011a). “Complete Al-Si order in scapolite Me 37.5, ideally Ca3Na5[Al8Si16O48]Cl(CO3), and implications for antiphase domain boundaries (APBs),Can. Mineral. 49, 581586.CrossRefGoogle Scholar
Antao, S. M. and Hassan, I. (2011b). “The structures of marialite (Me 6) and meionite (Me 93) in space groups P42/n and I4/m, and the absence of phase transitions in the scapolite series,Powder Diffr. (USA) 26, 119125.Google Scholar
Antao, S. M. and Hassan, I. (2008a). “Increase in Al-Si and Na-Ca disorder with temperature in scapolite Me 32.9,Can. Mineral. 46, 15771591.Google Scholar
Antao, S. M. and Hassan, I. (2008b). “Unusual Al-Si ordering in calcic scapolite, Me 79.6, with increasing temperature,Am. Mineral. (USA) 93, 14701477.Google Scholar
Antao, S. M., Hassan, I., Wang, J., Lee, P. L., and Toby, B. H. (2008). “State-of-the-art high-resolution powder X-ray diffraction (HRPXRD) illustrated with Rietveld structure refinement of quartz, sodalite, tremolite, and meionite,Can. Mineral. 46, 15011509.CrossRefGoogle Scholar
Deer, W. A., Howie, R. A., and Zussman, J. (1992). An Introduction to the Rock-Forming Minerals (John Wiley, New York, NY), 2nd ed. Google Scholar
Evans, B. W., Shaw, D. M., and Haughton, D. R. (1969). “Scapolite stoichiometry,Contrib. Mineral. Petrol. 24, 293305.CrossRefGoogle Scholar
Hassan, I. and Buseck, P. R. (1988). “HRTEM characterization of scapolite solid solutions,Am. Mineral. (USA) 73, 119134.Google Scholar
Hawthorne, F. C. and Sokolova, E. (2008). “The crystal chemistry of the scapolite-group minerals. II. The origin of the I4/m ←→  P42/n phase transition and the nonlinear variations in chemical composition,Can. Mineral. 46, 15551575.Google Scholar
Jiang, S. Y., Palmer, M. R., Xue, C. J., and Li, Y. H. (1994). “Halogen-rich scapolite-biotite rocks from the Tongmugou Pb-Zn deposit, Qinling, north-western China: implications for the ore-forming process,Mineral. Mag. 58, 543552.CrossRefGoogle Scholar
Kullerud, K. and Erambert, M. (1999). “Cl-scapolite, Cl-amphibole, and plagioclase equilibria in ductile shear zones at Nusfjord, Lofoten, Norway: implications for fluid compositional evolution during fluid-mineral interaction in the deep crust,Geochim. Cosmochim. Acta 63, 38293844.CrossRefGoogle Scholar
Larson, A. C. and Von Dreele, R. B. (2000). General Structure Analysis System (GSAS). Report, LAUR 86–748. Los Alamos National Laboratory.Google Scholar
Lee, P. L., Shu, D., Ramanathan, M., Preissner, C., Wang, J., Beno, M. A., Von Dreele, R. B., Ribaud, L., Kurtz, C., Antao, S. M., Jiao, X., and Toby, B. H. (2008). “A twelve-analyzer detector system for high-resolution powder diffraction,J. Synchrotron Radiat. (Denmark) 15, 427432.CrossRefGoogle ScholarPubMed
Lin, S. B. and Burley, B. J. (1973a). “Crystal structure of a sodium and chlorine-rich scapolite,Acta Crystallogr. B29, 12721278.CrossRefGoogle Scholar
Lin, S. B. and Burley, B. J. (1973b). “The crystal structure of meionite,Acta Crystallogr. B29, 20242026.Google Scholar
Lin, S. B. and Burley, B. J. (1973c). “On the weak reflections violating body-centered symmetry in scapolites,Tschermaks Mineralogisch-Petrologische Mitteilungen 20, 2844.CrossRefGoogle Scholar
Lovering, J. F. and White, A. J. R. (1969). “Granulitic and eclogitic inclusions from basic pipes at Delegate, Australia,Contrib. Mineral. Petrol. 21, 952.CrossRefGoogle Scholar
Moecher, D. P. and Essene, E. J. (1990). “Phase-equilibria for calcic scapolite, and implications of variable Al-Si disorder for P-T, T-X CO2 , and a-X relations,J. Petrol. 31, 9971024.CrossRefGoogle Scholar
Moecher, D. P. and Essene, E. J. (1991). “Calculation of CO2 activities using scapolite equilibria: constraints on the presence and composition of a fluid phase during high-grade metamorphism,Contrib. Mineral. Petrol. 108, 219240.Google Scholar
Rietveld, H. M. (1969). “A profile refinement method for nuclear and magnetic structures,J. Appl. Crystallogr. (Denmark) 2, 6571.Google Scholar
Seto, Y., Shimobayashi, N., Miyake, A., and Kitamura, M. (2004). “Composition and I4/m-P42/n phase transition in scapolite solid solutions,Am. Mineral. (USA) 89, 257265.Google Scholar
Shaw, D. M. (1960a). “The geochemistry of scapolite. Part I. Previous work and general mineralogy,J. Petrol. 1, 218260.Google Scholar
Shaw, D. M. (1960b). “The geochemistry of scapolite. Part II. Trace elements, petrology, and general geochemistry,J. Petrol. 1, 261285.Google Scholar
Sherriff, B. L., Sokolova, E. V., Kabalov, Y. K., Teertstra, D., Kunath-Fandrei, G., Goetz, S., and Jäger, C. (1998). “Intermediate scapolite: 29Si MAS and 27Al SATRAS NMR spectroscopy and Rietveld structure-refinement,Can. Mineral. 36, 12671283.Google Scholar
Sherriff, B. L., Sokolova, E. V., Kabalov, Y. K., Jenkins, D. M., Kunath-Fandrei, G., Goetz, S., Jäger, C., and Schneider, J. (2000). “Meionite: Rietveld structure-refinement, 29Si MAS and 27Al SATRAS NMR spectroscopy, and comments on the marialite-meionite series,Can. Mineral. 38, 12011213.CrossRefGoogle Scholar
Sokolova, E. and Hawthorne, F. C. (2008). “The crystal chemistry of the scapolite-group minerals. I. Crystal structure and long-range order,Can. Mineral. 46, 15271554.CrossRefGoogle Scholar
Sokolova, E. V., Kabalov, Y. K., Sherriff, B. L., Teertstra, D. K., Jenkins, D. M., Kunath-Fandrei, G., Goetz, S., and Jäger, C. (1996). “Marialite: Rietveld structure-refinement and 29Si MAS and 27Al satellite transition NMR spectroscopy,Can. Mineral. 34, 10391050.Google Scholar
Sokolova, E. V., Gobechiya, E. R., Zolotarev, A. A., and Kabalov, Y. K. (2000). “Refinement of the crystal structures of two marialites from the Kukurt deposit of the east Pamirs,Crystallogr. Rep. 45, 934938.Google Scholar
Teertstra, D. K. and Sherriff, B. L. (1996). “Scapolite cell-parameter trends along the solid-solution series,Am. Mineral. (USA) 81, 169180.CrossRefGoogle Scholar
Teertstra, D. K. and Sherriff, B. L. (1997). “Substitutional mechanisms, compositional trends and the end-member formulae of scapolite,Chem. Geol. (Isot. Geosci. Sect.) (Netherlands) 136, 233260.Google Scholar
Teertstra, D. K., Schindler, M., Sherriff, B. L., and Hawthorne, F. C. (1999). “Silvialite, a new sulfate-dominant member of the scapolite group with an Al-Si composition near the 14/m-P42/n phase transition,Mineral. Mag. 63, 321329.Google Scholar
Toby, B. H. (2001). “EXPGUI, a graphical user interface for GSAS,J. Appl. Crystallogr. 34, 210213.Google Scholar
Wang, J., Toby, B. H., Lee, P. L., Ribaud, L., Antao, S. M., Kurtz, C., Ramanathan, M., Von Dreele, R. B., and Beno, M. A. (2008). “A dedicated powder diffraction beamline at the advanced photon source: commissioning and early operational results,Rev. Sci. Instrum. (USA) 79, 085105.Google Scholar
Zolotarev, A. A. (1996). “Once more on isomorphic schemes and isomorphic series in the scapolite group,Zap. Vser. Mineral. Obshchest. 125, 6973.Google Scholar
Zolotarev, A. A., Petrov, T. G., and Moshkin, S. V. (2003). “Peculiarities of chemical compositions of the scapolite group minerals,Zap. Vser. Mineral. Obshchest. 132, 6384.Google Scholar