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The Role of H3O+ in the Crystal Structure of Illite

Published online by Cambridge University Press:  01 January 2024

Fernando Nieto ,
Marcello Mellini  and
Isabel Abad
Fernando Nieto*
Affiliation:
Departamento de Mineralogía y Petrología and IACT, Universidad de Granada, CSIC, Av. Fuentenueva, 18002 Granada, Spain
Marcello Mellini
Affiliation:
Dipartimento di Scienze della Terra, Università di Siena, Via Laterina 8, 53100 Siena, Italy
Isabel Abad
Affiliation:
Departamento de Geología, Universidad de Jaén, Campus Las Lagunillas, 23071 Jaén, Spain
*
* E-mail address of corresponding author: [email protected]
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Abstract

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In spite of decades of research on the subject, the crystal structure of illite is still poorly understood. The purpose of this study was to address this problem by investigating the nature of the interlayer content in illite IMt-2 from Silver Hill, Montana, using analytical transmission electron microscopy (ATEM), thermogravimetry (TG), and X-ray powder diffraction (XRPD) analyses. The ATEM data, together with literature and TG results, yielded the formula K0.70a0.01(H2O)0.42 (Al1.53Fe2+0.06Fe3+0.19Mg0.28)Σ−2.06(Si3.44Al0.56)O10(OH)2 or, assuming the presence of H3O+, K0.69Na0.01(H3O)+0.28(Al1.47Fe2+0.06Fe3+0.19Mg0.28)Σ−1.99(Si3.40Al0.60)O10(OH)2. The first formula indicates surplus interlayer and octahedral species, whereas the second shows no excess. The XRPD data were refined by Rietveld techniques, down to an Rp factor of 10.48–13.8%. The mineral composition consists largely of illite-2M1, illite-1M, and minor quartz. Although the refinement accuracy is limited by the intrinsic poor quality diffraction of the illites, the partially refined model is consistent with the chemical composition; in particular, attempts to introduce octahedral cations in excess of 2 were fruitless. All the results support the simple structural model, by which the illite structure strictly corresponds to a dioctahedral mica with H3O+ replacing K. As a consequence, the crystalchemical formula of illites should be calculated on the basis of six tetrahedral plus octahedral cations.

Keywords

CompositionHydroniumIlliteWater
Type
Article
Information
Clays and Clay Minerals , Volume 58 , Issue 2 , April 2010 , pp. 238 - 246
Copyright
Copyright © Clays and Clay Minerals 2010

References

Abad, L. Nieto, F. Peacor, D.R. and Velilla, N., 2003 Prograde and retrograde diagenetic and metamorphic evolution in metapelitic rocks of Sierra Espuna (Spain) Clay Minerals 38 1–23 10.1180/0009855033810074.CrossRefGoogle Scholar
Abad, L. Nieto, F. Gutierrez-Alonso, G. Do Campo, M. Lopez-Munguira, A. and Velilla, N., 2006 Illitic substitution in micas of very low-grade metamorphic clastic rocks European Journal of Mineralogy 18 59–69 10.1127/0935-1221/2006/0018-0059.CrossRefGoogle Scholar
Brown, G. and Norrish, K., 1952 Hydrous micas Mineralogical Magazine 29 929–932 10.1180/minmag.1952.029.218.04.CrossRefGoogle Scholar
Chen, T. and Wang, H.J., 2007 Determination of layer stacking microstructures and intralayer transition of illite polytypes by high-resolution transmission electron microscopy (HRTEM) American Mineralogist 92 926–932 10.2138/am.2007.2293.CrossRefGoogle Scholar
Cliff, G. and Lorimer, G.W., 1975 The quantitative analysis of thin specimens Journal of Microscopy 103 203–207 10.1111/j.1365-2818.1975.tb03895.x.CrossRefGoogle Scholar
Coelho, A.A., 2000 Whole-profile structure solution from powder diffraction data using simulated annealing Journal of Applied Crystallography 33 899–908 10.1107/S002188980000248X.CrossRefGoogle Scholar
Dong, H. and Peacor, D.R., 1996 TEM observations of coherent stacking relations in smectite, I/S and illite of shales: evidence for MacEwan crystallites and dominance of 2M 1 polytypism Clays and Clay Minerals 44 257–275 10.1346/CCMN.1996.0440211.CrossRefGoogle Scholar
Drits, V.A. and McCarty, D.K., 2007 The nature of structure-bonded H2O in illite and leucophyllite from dehydration and dehydroxylation experiments Clays and Clay Minerals 55 45–58 10.1346/CCMN.2007.0550104.CrossRefGoogle Scholar
Drits, V.A. and Zviagina, B.B., 2009 Trans-vacant and cis-vacant 2:1 layer silicates: structural features, identification and occurrence Clays and Clay Minerals 57 405–415 10.1346/CCMN.2009.0570401.CrossRefGoogle Scholar
Frey, M. and Frey, M., 1987 Very low-grade metamorphism of clastic sedimentary rocks Low-temperature Metamorphism UK Blackie, Glasgow 9–58.Google Scholar
Gailhanou, H. van Miltenburg, J.C. Rogez, J. Olives, J. Amouric, M. Gaucher, E.C. and Blanc, P., 2007 Thermodynamic properties of anhydrous smectite MX-80, illite IMt-2 and mixed-layer illite-smectite ISCz-1 as determined by calorimetric methods. Part I: Heat capacities, heat contents and entropies Geochimica et Cosmochimica Acta 71 5463–5473 10.1016/j.gca.2007.09.020.CrossRefGoogle Scholar
Gualtieri, A.F. Ferrari, S. Leoni, M. Grathoff, G. Hugo, R. Shatnawi, M. Paglia, G. and Billinge, S., 2008 Structural characterization of the clay mineral illite-IM Journal of Applied Crystallography 41 402–415 10.1107/S0021889808004202.CrossRefGoogle Scholar
Guidotti, C.V. and Dyar, M.D., 1991 Ferric iron in metamorphic biotite and its petrologic and crystallochem-ical implications American Mineralogist 76 161–175.Google Scholar
Hower, J. and Mowatt, T.C., 1966 Mineralogy of illites and mixed-layer illite/montmorillonites American Mineralogist 51 825–854.Google Scholar
Levien, L. Prewitt, C.T. and Weidner, D.J., 1980 Structure and elastic properties of quartz at pressure American Mineralogist 65 920–930.Google Scholar
Lliang, J.J. and Hawthorne, F.C., 1996 Rietveld refinement of micaceous materials: muscovite-2M 1, a comparison with single-crystal structure refinement The Canadian Mineralogist 34 115–122.Google Scholar
Merriman, R.J. Peacor, D.R., Frey, M. Robinson, D., 1999 Very low-grade metapelites: mineralogy, microfabrics and measuring reaction progress Low-grade Metamorphism Oxford, UK Blackwell Science 10–60.Google Scholar
Nadeau, P.H. Wilson, M.J. McHardy, W.J. and Tait, J.M., 1984 Interparticle diffraction: a new concept for inter-stratified clays Clay Minerals 19 757–769 10.1180/claymin.1984.019.5.06.CrossRefGoogle Scholar
Nieto, F., 2002 Characterization of coexisting NH4- and K-micas in very low-grade metapelites American Mineralogist 87 205–216 10.2138/am-2002-2-302.CrossRefGoogle Scholar
Nieto, F. Ortega-Huertas, M. Peacor, D. and Arostegui, J., 1996 Evolution of illite/smectite from early diagenesis through incipient metamorphism in sediments of the Basque-Cantabrian Basin Clays and Clay Minerals 44 304–323 10.1346/CCMN.1996.0440302.CrossRefGoogle Scholar
Parra, T. Vidal, O. and Agaard, A., 2002 A thermodynamic model for Fe-Mg dioctahedral K white micas using data from phase-equilibrium experiments and natural pelitic assemblages Contributions to Mineralogy and Petrology 143 706–732 10.1007/s00410-002-0373-6.CrossRefGoogle Scholar
Peacor, D.R. Bauluz, B. Dong, H. Tillick, D. and Yan, Y., 2002 Transmission and analytical electron microscopy evidence for high Mg contents of 1M illite: Absence of 1M polytypism in normal prograde diagenetic sequences of pelitic rocks Clays and Clay Minerals 50 757–765 10.1346/000986002762090281.CrossRefGoogle Scholar
Rieder, M. Cavazzini, G. D’Yakonov, Y.S. Kamanetskii, V.A.F. Gottardi, G. Guggenheim, S. Koval, P.K. Müller, G. Neiva, A.M.R. Radoslovich, E.W. Robert, J.L. Sassi, F.P. Takeda, H. Weiss, Z. and Wones, D.R., 1998 Nomenclature of the micas The Canadian Mineralogist 36 1–8.Google Scholar
Rodriguez-Carvajal, J., 2001 An introduction to the program FullProßOOO .Google Scholar
Rosenberg, P.E., 2002 The nature, formation, and stability of end-member illite: A hypothesis American Mineralogist 87 103–107 10.2138/am-2002-0111.CrossRefGoogle Scholar
Vidal, O. and Parra, T., 2000 Exhumation paths of high-pressure metapelites obtained from local equilibria for chlorite-phengite assemblages Geological Journal 35 139–161 10.1002/gj.856.CrossRefGoogle Scholar