Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-12-03T18:25:51.491Z Has data issue: false hasContentIssue false
  • English
  • Français

Synthetic amphiboles and triple-chain silicates in the system Na2O-MgO-SiO2-H2O: phase characterization, compositional relations and excess H

Published online by Cambridge University Press:  05 July 2018

W. V. Maresch ,
M. D. Welch ,
M. Gottschalk ,
W. Ruthmann ,
M. Czank  and
S. E. Ashbrook
W. V. Maresch*
Affiliation:
Institute for Geology, Mineralogy und Geophysics, Ruhr-University Bochum, 44780 Bochum, Germany
M. D. Welch
Affiliation:
Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
M. Gottschalk
Affiliation:
Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences, Section 3.3, Chemistry and Physics of Earth Materials, Telegrafenberg D322, 14473 Potsdam, Germany
W. Ruthmann
Affiliation:
Institute for Geology, Mineralogy und Geophysics, Ruhr-University Bochum, 44780 Bochum, Germany
M. Czank
Affiliation:
Institute of Geosciences, Christian-Albrechts-University Kiel, 24098 Kiel, Germany
S. E. Ashbrook
Affiliation:
School of Chemistry, University of St Andrews, St Andrews KYI 6 9ST, UK
*
* E-mail: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

The presence of structural OH in amphiboles in excess of the usual two OH per formula has been debated for over 40 years (Gier et ah,1964; Leake et ah,1968). However, the reality of the excess-OH phenomenon is still an open question, because accurate water analyses of amphiboles are rarely available. In this study, we review the data available on the chemically simple synthetic system Na2O—MgO-SiO2-H2O (NMSH) and present new results from NMR, infrared spectroscopy, and X-ray-diffraction that allow re-interpretation of previous studies of NMSH amphiboles along the pseudobinary join between the two end-member compositions Na2Mg6Si8O22(OH)2 and Na3Mg5Si8O21(OH)3.

We show that there is extensive solid solution involving excess H at 650—750°C, but also document the presence of a wide miscibility gap below 600°C. This miscibility gap is defined by amphiboles very close to the end-member composition Na3Mg5Si8O22(OH)3 coexisting with amphiboles with compositions near the ‘normal’ Na2Mg6Si8O22(OH)2 end member.

We also report the characterization of triple-chain silicates (TCS) in the NMSH system and their phase relations with NMSH amphiboles. The upper thermal stability field of the key TCS Na2Mg4Si6O16(OH)2relative to its decomposition to two NMSH amphiboles with a combined equivalent composition has been determined and a pronounced backbend of the transformation boundary documented. Phase relations observed in synthesis experiments suggest that at 550—650°C all TCSs have compositions close to Na2Mg4Si6Oi6(OH)2. Infrared spectroscopy indicates that the TCS synthesized on this composition, studied in detail here, vary from end-member Na2Mg4Si6Oi6(OH)2 to binary solid solutions with less than ∼6 mol.% clinojimthompsonite component. No clear spectroscopic evidence for a ‘Drits’ component NaMg4Si6Oi5(OH)3 (Drits et al.,1975) has been found. Analysis of H2O by vacuum extraction and Karl-Fischer titration indicates large excesses of H2O in all the TCSs studied here that clearly exceed the amounts expected from (OH) groups alone. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) indicate that this excess H2O is structural. We propose that the excess H2O is likely to be molecular H2O located in the ^4-site channels. The observed backbend of the triple-chain decomposition curve is in agreement with a reaction involving dehydration and loss of this molecular H2O. However, the absolute amount of analysed molecular H2O exceeds that expected from the change in Clapeyron slope alone.

While demonstrating the reality of excess OH in amphiboles, the evidence presented in this paper also points to interesting avenues for future research on both amphiboles and TCSs, such as understanding the dynamics and enhanced crystal chemistry of excess OH and molecular H2O in pyriboles.

Keywords

NMSH systemamphiboletriple-chain silicateexcess OH
Type
Research Article
Information
Mineralogical Magazine , Volume 73 , Issue 6 , December 2009 , pp. 957 - 996
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2009

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

4

present address: GGU-Gesellschaft fur Grundbau und Umwelttechnik mbH, In den Ungleichen 3, 39171 Osterweddingen, Germany

References

Ams, B.E., Jenkins, D.M., Boerio-Goates, I, Morcos, R.M., Navrotsky, A. and Bozhilov, K.N. (2009) Thermochemistry of a synthetic Na-Mg-rich triple-chain silicate: determination of thermodynamic variables. American Mineralogist, 94, 1242–1254.CrossRefGoogle Scholar
Bunge, H.-J. (1982) Texture Analysis in Materials Science, Mathematical Methods. Butterworths, London, 593 pp.Google Scholar
Burnham, C.W., Holloway, J.R. and Davis, N.F. (1969) Thermodynamic properties of water to 1000°C and 10000 bars. Geological Society of America Special Paper, 132, 96 pp.Google Scholar
Caglioti, G., Paoletti, A. and Ricci, F.P. (1958) Choice of collimators for crystal spectrometer for neutron diffraction. Nuclear Instruments, 3, 223–228.CrossRefGoogle Scholar
Camara, F., Oberti, R., Iezzi, G. and Delia Ventura, G. (2003) The P11/m ⇌ C2/m phase transition in synthetic amphibole NaNaMgMg5Si8O22(OH)2: Thermodynamics and crystal-chemical evaluation. Physics and Chemistry of Minerals, 30, 570–581.Google Scholar
Camara, F., Oberti, R., Delia Ventura, G., Welch, M.D. and Maresch, W.V. (2004) The crystal structure of synthetic NaNa2Mg5Si8O21(OH)3, a triclini. C amphibole with a triple-cell and H excess. American Mineralogist, 89, 1464–1473.Google Scholar
Carman, J.H. (1974) Synthetic sodium phlogopite and its two hydrates: stabilities, properties, and mineralogic implications. American Mineralogist, 59, 261–273.Google Scholar
Drits, V.A., Goncharov, Y.I., Aleksandrova, V.A., Khadzhi, V.E. and Dmitrik, A.L. (1975) A new type of strip silicate. Soviet Physics and Crystallography, 19, 737–741.Google Scholar
Franz, G. and Althaus, E. (1974) Synthesis and thermal stability of 2'/2-octahedral sodium mica, NaMg2 5[(OH)2Si4O10]. Contributions to Mineralogy and Petrology, 46, 227–232.CrossRefGoogle Scholar
Gibbs, G.V., Miller, J.L. and Shell, H.R. (1962) Synthetic fluor-magnesio-richterite. American Mineralogist, 47, 75–82.Google Scholar
Gier, T.E., Cox, N.L. and Young, H.S. (1964) The hydrothermal synthesis of sodium amphiboles. Inorganic Chemistry, 3, 1001–1004.CrossRefGoogle Scholar
Graham, CM., Maresch, W.V., Welch, M.D. and Pawley, A.R. (1989) Experimental studies on amphiboles: a review with thermodynamic perspectives. European Journal of Mineralogy, 1, 63–83.CrossRefGoogle Scholar
Graham, CM., Tareen, J.A.K., McMillan, P.F. and Lowe, B.M. (1992) An experimental and thermo-dynamic study of cymrite and celsian stability in the system BaO-Al2O3-SiO2-H2O. European Journal of Mineralogy, 4, 251–269.CrossRefGoogle Scholar
Griffiths, P.R. and de Haseth, J.A. (1986) Fourier Transform Infrared Spectroscopy. John Wiley and Sons, New York, 529 pp.Google Scholar
Hamilton, D.L. and Henderson, C.M.B. (1968) The preparation of silicate compositions by a gelling method. Mineralogical Magazine, 36, 832–838.CrossRefGoogle Scholar
Hawthorne, F.C. (1981) Crystal chemistry of the amphiboles. Pp. 1—102 in: Amphiboles and other hydrous Pyriboles - Mineralogy (Veblen, D. R., editor). Reviews in Mineralogy, 9A, Mineralogical Society of America, Chantilly, Virginia. USA.Google Scholar
Hawthorne, F.C and Oberti, R. (2007) Amphiboles: crystal chemistry. Pp. 1—54 in: Amphiboles: Crystal Chemistry, Occurrence and Health Issues (Hawthorne, F.C., Oberti, R., Delia Ventura, G. and Mottana, A., editors). Reviews in Mineralogy and Geochemistry, 67, Mineralogical Society of America, Chantilly, Virginia. USA.CrossRefGoogle Scholar
Hawthorne, F.C, Oberti, R. and Sardone, N. (1996) Sodium at the A-site in clinoamphiboles: the effects of composition on patterns of order. The Canadian Mineralogist, 34, 577–593.Google Scholar
Iezzi, G., Delia Ventura, G., Oberti, R., Camara, F. and Holtz, F. (2004) Synthesis and crystal-chemistry of Na(NaMg)Mg5Si8O22(OH)2,. Fl-Jm amphibole. American Mineralogist, 89, 640–646.CrossRefGoogle Scholar
Iezzi, G., Gatta, G.D., Kockelmann, W., Delia Ventura, G., Rinaldi, R., Schafer, W., Piccinini, M. and Gaillard, F. (2005) Low-r neutron powder-diffraction and synchrotron-radiation IR study of synthetic amphibole Na(NaMg)Mg5Si8O22(OH)2 . American Mineralogist, 90, 695–700.CrossRefGoogle Scholar
Iezzi, G., Liu, Z. and Delia Ventura, G. (2006) Synchrotron infrared spectroscopy of synthetic Na(NaMg)Mg5Si8O22(OH)2 up to 30 GPa: Insight on a new high-pressure amphibole polymorph. American Mineralogist, 91, 479–482.CrossRefGoogle Scholar
Iezzi, G., Liu, Z. and Delia Ventura, G. (2009) Synthetic ANaB(NaxLi1.xMg)cMg5SiO22(OH)2 (wit. x = 0.6, 0.2 and 0) P2\/m amphiboles at high pressure: a synchrotron infrared study. Physics and Chemistry of Minerals, 36, 343–354.Google Scholar
Iiyama, J.T. (1963) Synthese hydrothermale a 750°C, 1000 bars dans le systeme Na2O-MgO-Al2O3-SiO2-H2O d'amphiboles orthorhombiques et monoclini-ques [Hydrothermal synthesis of orthorhombic and monoclinic amphiboles at 750°C, 1000 bars in the system Na2O-MgO-Al2O3-SiO2-H2O]. Comptes Rendues Academie de Sciences Paris, 256, 966–967.Google Scholar
Johannes, W. and Schreyer, W. (1981) Experimental introduction of CO2 and H2O into Mg-cordierite. American Journal of Science, 281, 299–317.CrossRefGoogle Scholar
Jones, B.F. and Galan, E. (1988) Sepiolite and palygorskite. Pp. 631—674 in: Hydrous Phyllosilicates (exclusive of Micas) (Bailey, S. W., editor). Reviews in Mineralogy, 19, Mineralogical Society of America, Chantilly, Virginia. USA.Google Scholar
Kuhn, A. (1974) Synthese und Eigenschaften, insbeson-dere Infrarot-Spektren von Amphibolen in den Systemen Na2O-MgO-SiO2-H2O bzw. D2O [Synthesis and properties, with emphasis on infrared spectra, of amphiboles in the systems Na2O-MgO-SiO2-H2O or -D2OJ. Diploma Thesis, Ruhr University Bochum, Germany, 68 pp.Google Scholar
Larson, A.C. and von Dreele, R.B. (2004) Generalized structure analysis system. Alamos National Laboratory Report LAUR 96-748. Los Alamos National Laboratory, New Mexico, USA.Google Scholar
Leake, B.E. (1968) A catalog of analyzed calciferous and subcalciferous amphiboles together with their nomenclature and associated minerals. Geological Society of America Special Paper, 98, 210 pp.Google Scholar
Leake, B.E., Woolley, A.R., Arps, C.E.S., Birch, W.D., Gilbert, M.C., Grice, J.D., Hawthorne, F.C, Kato, A., Kisch, H.J., Krivovichev, V.G., Linthout, K., Laird, J., Mandarino, J., Maresch, W.V., Nickel, E.H., Rock, N.M.S., Schumacher, J.C., Smith, D.C., Stephenson, N.C.N., Ungaretti, L., Whittaker, E.J.W. and Youzhi, G. (1997) Nomenclature of amphiboles: Report of the subcommittee on amphiboles of the International Mineralogical Association Commission on New Minerals and Mineral Names. Mineralogical Magazine, 71, 295–321.CrossRefGoogle Scholar
Liu, S., Welch, M.D., Klinowski, J. and Maresch, W.V. (1996) A monoclinic/triclinic phase transition in amphibole: I. A solid-state NMR study. European Journal of Mineralogy, 8, 223–229.CrossRefGoogle Scholar
Maresch, W.V. (1977) Experimental studies on glauco-phane: An analysis of present knowledge. Tectonophysics, 43, 109–125.CrossRefGoogle Scholar
Maresch, W.V. (2002) New insights on the stability relations of hydrous chain silicates in the system Na2O-MgO-SiO2-H2O at pressures up to 1 GPa. 18thIMA Meeting, Edinburgh, 2002, Programme with Abstracts, 84.Google Scholar
Maresch, W.V. and Czank, M. (1983) Problems of compositional and structural uncertainty in synthetic hydroxyl-amphiboles; with an annotated atlas of the Realbau. Periodico di Mineralogia, 52, 463–542.Google Scholar
Maresch, W.V. and Czank, M. (1985) The optical and X-ray properties of Li2Mg2[Si4On], a new type of chain silicate. Neues Jahrbuch fur Mineralogie Monatshefte, 289–297.Google Scholar
Maresch, W.V. and Czank, M. (2007) The significance of the reaction path in synthesizing single-phase amphibole of defined composition. Pp. 287—322 in: Amphiboles: Crystal Chemistry, Occurrence and Health Issues (Hawthorne, F. C., Oberti, R., Delia Ventura, G. and Mottana, A., editors). Reviews in Mineralogy and Geochemistry, 67, Mineralogical Society of America, Chantilly, Virginia. USA.Google Scholar
Maresch, W.V. and Langer, K. (1976) Synthesis, lattice constants and OH-valence vibrations of an orthorhombic amphibole with excess OH in the system Li2O-MgO-SiO2-H2O. Contributions to Mineralogy and Petrology, 56, 27–34.CrossRefGoogle Scholar
Maresch, W.V., Ruthmann, W. and Langer, K. (1990) A third type of site environment for hydrogen in chain silicates? Terra Abstracts, 2, 88.Google Scholar
Maresch, W.V., Miehe, G., Czank, M., Fuess, H. and Schreyer, W. (1991) Triclinic amphibole. European Journal of Mineralogy, 3, 899–903.CrossRefGoogle Scholar
Maresch, W.V., Czank, M. and Schreyer, W. (1994) Growth mechanisms, structural defects and composition of synthetic tremolite: What are the effects on macroscopic properties. Contributions to Mineralogy and Petrology, 118, 297–313.CrossRefGoogle Scholar
Medenbach, O., Maresch, W.V., Mirwald, P.W. and Schreyer, W. (1980) Variation of refractive index of synthetic Mg-cordierite with H2O-content. American Mineralogist, 65, 367–373.Google Scholar
Mirwald, P.W., Maresch, W.V. and Schreyer, W. (1979) Der Wassergehalt von Mg-Cordierit zwischen 500°C und 800°C sowie 0.5 und 11 kbar [The water content of Mg-cordierite between 500°C and 800°C as well as between 0.5 and 11 kbar]. Fortschritte der Mineralogie, 57, Beiheft 1, 101–102.Google Scholar
Mirwald, P.W., Jochum, C. and Maresch, W.V. (1986) Rate studies on hydration and dehydration of synthetic Mg-cordierite. Materials Science Forum, 5, 113–122.CrossRefGoogle Scholar
Oberti, R., Delia Ventura, G., Ottolini, L. and Prella, D. (2000). Excess OH in amphiboles: a structural model obtained by combining structure refinement, complete chemical characterisation, and FTIR spectro-scopy. Plinius, 24, 157.Google Scholar
Pankrath, R. and Langer, K. (2002) Molecular water in beryl, VIAl2[Be3Si6O18]-;!H2O, as a function of pressure and temperature: An experimental study. American Mineralogist, 87, 238–244.CrossRefGoogle Scholar
Raudsepp, M., Turnock, A.C. and Hawthorne, F.C. (1991) Amphibole synthesis at low pressure: what grows and what doesn't. European Journal of Mineralogy, 3, 983–1004.CrossRefGoogle Scholar
Robert, J.-L., Delia Ventura, G. and Thauvin, J.-L. (1989) The infrared OH-stretching region of synthetic richterites in the system Na2O-K2O-CaO-MgO-SiO2-H2O-HF. European Journal of Mineralogy, 1, 203–211.CrossRefGoogle Scholar
Ruthmann, W. (1989) Synthese, Charakterisierung und Stabilitatsbeziehungen von Dreifachkettensilikaten im System Na2O-MgO-SiO2-H2O [Synthesis, char-acterization and stability relations of triple-chain silicates in the system Na2O-MgO-SiO2-H2O]. Diploma Thesis, Ruhr-University Bochum, Germany, 85 pp.Google Scholar
Schmidt, I. (1989) Kristallchemische Charakterisierung von Kettensilikaten im System Na2O-MgO-SiO2(Al2O3)-H2O, insbesondere mit Hilfe von Elektronenmikroskopie und Elektronenbeugung [Crystal-chemical characterization of chain silicates in the system Na2O-MgO-SiO2(Al2O3)-H2O, with emphasis on electron microscopy and electron diffraction]. Diploma Thesis, Kiel University, Germany, 92 pp.Google Scholar
Schreyer, W. (1985) Experimental studies on cation substitutions and fluid incorporation in cordierite. Bulletin Mineralogique, 108, 273–291.CrossRefGoogle Scholar
Schreyer, W. and Yoder, H.S. Jr. (1964) The system Mg-cordierite-H2O and related rocks. Neues Jahrbuch fur Mineralogie Abhandlungen, 101, 271–342.Google Scholar
Tateyama, H., Shimoda, S. and Sudo, T. (1978) Synthesis and crystal structure of a triple-chain silicate Na2Mg4Si6Oi6(OH)2 . Contributions to Mineralogy and Petrology, 66, 149–156.CrossRefGoogle Scholar
Veblen, D.R. (1981) Non-classical pyriboles and polysomatic reactions in biopyriboles. Pp. 189—236 in: Amphiboles and other hydrous Pyriboles -Mineralogy (Veblen, D. R., editor). Reviews in Mineralogy, 9A, Mineralogical Society of America, Chantilly, Virginia. USA.CrossRefGoogle Scholar
Veblen, D.R. and Burnham, C.W. (1978) New biopyriboles from Chester, Vermont; II, The crystal chemistry of jimthompsonite, clinojimthompsonite, and chesterite, and the amphibole-mica reaction. American Mineralogist, 63, 1053–1073.Google Scholar
von Dreele, R.B. (1997) Quantitative texture analysis by Rietveld refinement. Journal of Applied Crystallography, 30, 517–525.CrossRefGoogle Scholar
Welch, M.D. (1987) Experimental studies of selected amphiboles in the system Na2O-CaO-MgO-Al2O3-SiO2-SiF4-H2O and its subsystems. PhD thesis, University of Edinburgh. 194 pp.Google Scholar
Welch, M.D., Rocha, J. and Klinowski, J. (1992) Characterization of polysomatism in biopyriboles: double-/triple-chain lamellar intergrowths. Physics and Chemistry of Minerals, 18, 460–468.CrossRefGoogle Scholar
Welch, M.D., Liu, S. and Klinowski, I. (1998) 29Si MAS NMR systematics of calcic and sodic-calcic amphiboles. American Mineralogist, 83, 85–96.CrossRefGoogle Scholar
Welch, M.D., Camara, F., Delia Ventura, G. and Iezzi, G. (2007) Non-ambient in situ studies of amphiboles. Pp. 223–260 in: Amphiboles: Crystal Chemistry, Occurrence and Health Issues (Hawthorne, F.C., Oberti, R., Delia Ventura, G. and Mottana, A., editors). Reviews in Mineralogy and Geochemistry, 67, Mineralogical Society of America, Chantilly, Virginia. USA.CrossRefGoogle Scholar
Witte, P. (1975) Synthese und Stabilitdt von Amphibolphasen und wasserfreien Na-Mg-Silikaten im System Na 2O-MgO-SiO 2-H 2O, die Kompatibilitatsbeziehungen innerhalb des Si-reichen Teils des quaternaren Systems oberhalb 600“C im Druckbereich 1 atm — 5 kb (H2O) und ihre petrologische Bedeutung [Synthesis and stability of amphibole phases and anhydrous Na-Mg-silicates in the system Na2O-MgO-SiO2-H2O, the compatibility relationships in the Si-rich part of the quaternary system above 600“C in the pressure range 1 atm — 5 kb (H2O) and their petrological significance]. Ph.D. Thesis, Ruhr-University Bochum, Germany, 256 pp.Google Scholar
Witte, P., Langer, K., Seifert, F. and Schreyer, W. (1969) Synthetische Amphibole mit OH UberschuB im System Na2O-MgO-SiO2-H2O [Synthetic amphi- boles with OH excess in the system Na2O-MgO-SiO2-H2O]. Naturwissenschaften, 56, 414–415.CrossRefGoogle Scholar