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American Mineralogist

Journal of Earth and Planetary Materials

Ed. by Baker, Don / Xu, Hongwu / Swainson, Ian

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Volume 101, Issue 6


Natural Mg-Fe clinochlores: enthalpies of formation and dehydroxylation derived from calorimetric study

Lyubov P. Ogorodova
  • Corresponding author
  • Geological Faculty, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119234, Russia
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/ Marina F. Vigasina
  • Geological Faculty, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119234, Russia
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/ Lyubov V. Melchakova
  • Geological Faculty, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119234, Russia
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/ Irina A. Kiseleva
  • Geological Faculty, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119234, Russia
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/ Victoria V. Krupskaya
  • Geological Faculty, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119234, Russia
  • Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS, Staromonetnii lane, 35, Moscow 109017, Russia
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/ Igor A. Bryzgalov
  • Geological Faculty, M.V. Lomonosov Moscow State University, Leninskie Gory, Moscow 119234, Russia
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Published Online: 2016-06-03 | DOI: https://doi.org/10.2138/am-2016-5572


This paper presents the results of the first experimental thermochemical investigation of two natural trioctahedral chlorites (clinochlores). The study was performed with the help of a high-temperature heat-flux Tian-Calvet microcalorimeter. The samples were characterized by X ray spectroscopy analysis, X ray powder diffraction, thermal analysis, and FTIR spectroscopy. The enthalpies of formation of clinochlores were found using the melt solution calorimetry method to be: –8806 ± 16 kJ/mol for composition (Mg4.9Fe0.32+Al0.8)[Si3.2Al0.8O10](OH)8 and –8748 ± 24 kJ/mol for composition (Mg4.2Fe0.62+Al1.2)[Si2.8Al1.2O10](OH)8. The experimental data for natural samples allowed calculating the enthalpies of formation for end-members and intermediate members of the clinochlore (Mg5Al)[Si3AlO10](OH)8 and chamosite (Fe5Al)[Si3AlO10](OH)8 series. An important feature of the clinochlore structure is the presence of two distinct hydroxyl-containing octahedral layers: the interlayer octahedral sheet and octahedral 2:1 layer; the enthalpies of water removal from these positions in clinochlore structure were determined as: 53 ± 20 kJ/(mol·H2O) and 131 ± 10 kJ/(mol·H2O), respectively. These obtained first thermodynamic characteristics of Mg-Fe clinochlores can be used for quantitative thermodynamic modeling of geological and industrial processes including clinochlores of different composition.

Key words: Clinochlore; chlorite; thermochemistry; microcalorimetry; enthalpy of dehydroxylation; enthalpy of formation

References cited

  • Aja, S.U. (2002) The stability of Fe-Mg clinochlores in hydrothermal solutions: II. Thermodynamic properties. Clays and Clay Minerals, 50, 591–600.Google Scholar

  • Bailey, S.W. (1988) Clinochlores: structures and crystal chemistry. Reviews in Mineralogy, 19, 398–404.Google Scholar

  • Berman, R.G. (1988) Internally-consistent thermodynamic data for minerals in the system Na2O-K2O-CaO-MgO-FeO-Fe2O3-Al2O3-SiO2-TiO2-H2O-CO2. Journal of Petrology, 29(2), 445–522.Google Scholar

  • Bertoldi, C., Dachs, E., and Appel, P. (2007) Heat-pulse calorimetry measurements on natural chlorite-group minerals. American Mineralogist, 92, 553–559.Google Scholar

  • Chernovsky, J.V. Jr. (1974) The upper stability of clinochlore at low pressure and the free energy of formation of Mg-cordierite. American Mineralogist, 59, 496–507.Google Scholar

  • Chukanov, N.V. (2014) Infrared Spectra of Mineral Species: Extended Library, 1703 p. Springer-Verlag, Dordrecht.Google Scholar

  • Dorogokupetz, P.I., and Karpov, I.K. (1984) Thermodynamics of Minerals and Mineral Equilibria, 184 p. Nauka, Novosibirsk.Google Scholar

  • Drits, V.A., and Kossovskaya, A.G. (1991) Clay Minerals: Mica, Clinochlores, 177 p. Nauka, Moscow.Google Scholar

  • Fawcett, J.J., and Yoder, H.S. (1966) Phase relations of chlorites in the system MgO-Al2O3-SiO2-H2O at 2 kbar water pressure. American Mineralogist, 51, 353–380.Google Scholar

  • Foldvari, M. (2011) Handbook of Thermogravimetric System of Minerals and its Use in Geological Practice, 180 p. Geological Institute of Hungary, Budapest.Google Scholar

  • Gailhanou, H., Rogez, J., van Miltenburg, J.C., van Genderen, A.C.C., Greneche, J.M., Gaucher, E.C., Crouzet, C., Touzelet, S., and Blanc, P. (2007) Experimental determination of thermodynamic properties of a clinochlore. Internal Meeting “Clays in natural & engineered barriers for radioactive waste confinement” (Sept. 17–19, 2007). Abstract, 355–356.Google Scholar

  • Gailhanou, H., Rogez, J., van Miltenburg, J.C., van Genderen, A.C.C., Greneche, J.M., Gills, C., Jalabert, D., Michau, N., Gaucher, E., and Blanc, P. (2009) Thermodynamic properties of clinochlore CCa-2. Heat capacities, heat contents and entropies. Geochimica et Cosmochimica Acta, 73, 4738–4749.Google Scholar

  • Guggenheim, S., Adams, J.M., Bain, D.C., Bergaya, F., Brigatti, M.F., Drits, V.A., Formoso, M.L.L., Galan, E., Kogure, T., and Stanjek, H. (2006) Summary of recommendations of nomenclature committees relevant to clay mineralogy: report of the association internationale pour l’etude des argiles (AIPEA) nomenclature committee for 2006. Clays and Clay Minerals, 54(6), 761–772.Web of ScienceGoogle Scholar

  • Helgeson, H.C., Delany, J.M., Nesbit, H.W., and Bira, D.K. (1978) Summery and critique of the thermodynamic properties of rock-forming minerals. American Journal of Science, 278A, 229 p.Google Scholar

  • Hemingway, B.S., Robie, R.A., Kittrick, J.A., Grew, E.S., Nelen, J.A., and London, D. (1984) The heat capacities of osumilite from 298.15 to 1000 K, the thermodynamic properties of two natural clinochlores to 500 K, and the thermodynamic properties of petalote to 1800 K. American Mineralogist, 69, 701–710.Google Scholar

  • Holland, T.J.B. (1989) Dependence of entropy on volume for silicate and oxide minerals: A review and a predictive model. American Mineralogist, 74, 5–13.Google Scholar

  • Holland, T.J.B., and Powell, R. (1998) An internally consistent thermodynamic data set for phases of petrological interest. Journal of Metamorphic Geology, 16, 309–343.Google Scholar

  • Holland, T.J.B., and Powell, R. (2011) An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids. Journal of Metamorphic Geology, 29, 333–383.Google Scholar

  • Jenkins, D.M. (1981) Experimental phase relations of hydrous peridotites modelled in the system H2O-CaO-MgO-Al2O3-SiO2. Contributions to Mineralogy and Petrology, 77, 166–176.Google Scholar

  • Jenkins, D.M., and Chernosky, J.V. (1986) Phase equilibria and crystallochemical properties of Mg-clinochlores. American Mineralogist, 71, 924–936.Google Scholar

  • Kestin, J., Sengers, J.V., Kamgar-Parsi, B., and Levelt Sengers, J.M.H. (1984) Thermophysical properties of fluid H2O. Journal of Physical & Chemical Reference Data, 13(1), 175–183.Google Scholar

  • Kiseleva, I.A. (1976) Thermodynamic properties and stability of pyrope. Geochemistry International, 13, 139–146.Google Scholar

  • Kiseleva, I.A., and Ogorodova, L.P. (1984) High temperature solution calorimetry for determining the enthalpies of formation for hydroxyl containing minerals such as talc and tremolite. Geochemistry International, 2, 36–46.Google Scholar

  • Kiseleva, I.A., Ogorodova, L.P., Topor, N.D., and Chigareva, O.G. (1979) Thermochemical study of the CaO–MgO–SiO2 system. Geochemistry International, 16, 122–134.Google Scholar

  • Kittrick, J.A. (1982) Solubility of two high-Mg and two high-Fe clinochlores using multiple equilibria. Clays and Clay Minerals, 30, 167–179.Google Scholar

  • Laird, J. (1988) Clinochlores: metamorphic petrology. Reviews in Mineralogy, 19, 405–454.Google Scholar

  • Navrotsky, A., and Coons, W.J. (1976) Thermochemistry of some pyroxenes and related compounds. Geochimica et Cosmochimica Acta, 40, 1281–1295.Google Scholar

  • Nriagu, J.O. (1975) Thermochemical approximations for clay minerals. American Mineralogist, 60, 834–839.Google Scholar

  • Ogorodova, L.P., Melchakova, L.V., Kiseleva, I.A., and Belitsky, I.A. (2003) Thermochemical study of natural pollucite. Thermochimica Acta, 403, 251–256.Google Scholar

  • Ogorodova, L.P., Kiseleva, I.A., Melchakova, L.V., Vigasina, M.F., and Krupskaya, V.V. (2013) Thermochemical study of natural montmorillonite. Geochemistry International, 51(6), 484–494.Web of ScienceGoogle Scholar

  • Ogorodova, L.P., Kiseleva, I.A., Vigasina, M.F., Kabalov, Y.K., Grishchenko, R.O., and Mel’chakova, L.V. (2014) Natural sepiolite: enthalpies of dehydration, dehydroxylation and formation derived from thermochemical studies. American Mineralogist, 99, 2369–2373.Google Scholar

  • Post, J.E., and Bish, D.L. (1989) Rietveld refinement of crystal structures using powder X ray diffraction data. Reviews in Mineralogy and Geochemistry, 20, 277–308.Google Scholar

  • Prieto, A.C., Dubessy, J., and Cathelineau, M. (1991) Structure-composition relationships in trioctahedral clinochlores: A vibrational spectroscopy study. Clays and Clay Minerals, 39, 531–539.Google Scholar

  • Robie, R.A., and Hemingway, B.S. (1995) Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar (105 pascals) pressure and at higher temperatures. U.S. Geological Survey Bulletin, 2131, 461 p.Google Scholar

  • Shvarov, Y.V. (2015) A suite of programs, OptimA, OptimB, OptimC, and OptimS compatible with the Unitherm database, for deriving the thermodynamic properties of aqueous species from solubility, potentiometry and spectroscopy measurements. Applied Geochemistry, 55, 17–27.Web of ScienceGoogle Scholar

  • Staudigel, H., and Schreyer, W. (1977) The upper thermal stability of clinochlore, Mg5Al[Si3AlO10](OH)8, at 10–35 kbar P(H2O). Contributions to Mineralogy and Petrology, 61, 187–198.Google Scholar

  • Tardy, Y., and Garrels, R.M. (1974) A method of estimating the Gibbs energies of formation of layer silicates. Geochimica et Cosmochimica Acta, 38, 1101–1116.Google Scholar

  • Valero, A., Valero, A., and Vieillard, P. (2012) The thermodynamic properties of the upper continental crust: Exergy, Gibbs free energy and enthalpy. Energy, 41, 121–127.Web of ScienceGoogle Scholar

  • Vieillard, P. (2002) A new method for the prediction of Gibbs free energies of formation of phillosilicates (10 and 14 Å) based on the electronegativity scale. Clays and Clay Minerals, 50, 352–363.Google Scholar

  • Villiéras, F., Yvon, J., François, M., Cases, J.M., Lhote, F., and Uriot J.-P. (1993) Micropore formation due to thermal decomposition of hydroxide layer of Mg-clinochlores: interactions with water. Applied Clay Science, 8, 147–168.Google Scholar

  • Villiéras, F., Yvon, J., Cases, J.M., de Donato, P., Lhote, F., and Baeza, R. (1994) Development of microporosity in clinochlore upon heating. Clays and Clay Minerals, 42, 679–688.Google Scholar

  • Zen, E-An. (1972) Gibbs free energy, enthalpy and entropy of ten rock-forming minerals: Calculations, discrepancies, implications. American Mineralogist, 57, 524–553.Google Scholar

About the article

Received: 2015-09-30

Accepted: 2016-01-22

Published Online: 2016-06-03

Published in Print: 2016-06-01

Citation Information: American Mineralogist, Volume 101, Issue 6, Pages 1431–1437, ISSN (Online) 1945-3027, ISSN (Print) 0003-004X, DOI: https://doi.org/10.2138/am-2016-5572.

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© 2016 by Walter de Gruyter Berlin/Boston.

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