Hostname: page-component-848d4c4894-xm8r8 Total loading time: 0 Render date: 2024-06-20T10:26:20.407Z Has data issue: false hasContentIssue false

Extremely Al-Depleted Chlorites From Dolomite Carbonatites of the Kovdor Ultramafic-Alkaline Complex, Kola Peninsula, Russia

Published online by Cambridge University Press:  01 January 2024

Nikita V. Chukanov*
Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow, Region 142432, Russia
Maria G. Krzhizhanovskaya
Department of Crystallography, Saint Petersburg State University, Universitetskaya Nab. 7/9, 199034 St. Petersburg, Russia
Igor V. Pekov
Faculty of Geology, Moscow State University, Vorobievy Gory, Moscow 119234, Russia
Dmitry A. Varlamov
Institute of Experimental Mineralogy, Russian Academy of Sciences, Chernogolovka, Moscow, Region 142432, Russia
Konstantin V. Van
Institute of Experimental Mineralogy, Russian Academy of Sciences, Chernogolovka, Moscow, Region 142432, Russia
Vera N. Ermolaeva
Institute of Experimental Mineralogy, Russian Academy of Sciences, Chernogolovka, Moscow, Region 142432, Russia
Svetlana A. Vozchikova
Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow, Region 142432, Russia
*E-mail address of corresponding author:


The problem to be solved is whether Al is a necessary component of Fe-Mg chlorites. Very unusual Al-depleted and Fe-enriched trioctahedral chlorites with the empirical formulae Na0.05Ca0.05(Fe2+3.01Mg2.01Ti0.14Fe3+0.04)Σ6.00[(Si3.53Fe3+0.41Al0.06)Σ4.00O10](OH)8·nH2O (Sample 1) and Na0.05Ca0.01(Fe2+3.26Mg1.97Fe3+0.75Mn0.01Ti0.01)Σ6.00[(Si3.16Fe3+0.75Al0.09)Σ4.00O10](OH)8 (Sample 2) have been discovered in Al-depleted dolomite carbonatites of the Kovdor complex of ultramafic, alkaline rocks and carbonatites, Kola Peninsula, Russia. The presence of substantial amounts of Ti in Sample 1 is another unusual feature of this mineral. In both samples, chlorites are intimately intergrown with cronstedtite-1T which is an indication of a low stability of chlorite structure in the absence of aluminum in the tetrahedral sheet. The crystal structure of chlorite in Sample 1 was solved by the Rietveld method. The mineral is triclinic (IIb-4-module), space group C-1, a = 5.4153(4), b = 9.3805(7), c = 14.5743(12) Å, α = 90.137(5)°, β = 96.928(5)°, γ = 90.043(6)°, V = 734.95(10) Å3, and Z = 2. A problem to be solved is how stable are Al-free chlorites belonging to the clinochlore–chamosite solid-solution series and whether their existence in natural mineral assemblages is possible. The results obtained indicate that even though Al-depleted chlorites belonging to the clinochlore–chamosite solid-solution series exist in Nature as metastable phases, these minerals are extremely rare and much less stable than Al-poor serpentines.

Copyright © Clay Minerals Society 2020

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.)


Back, M. E. (2018). Fleischer's Glossary of Mineral Species. Tucson, Arizona, USA: The Mineralogical Record Inc.Google Scholar
Bailey, S.W. (1988). Chlorites: Structures and crystal chemistry. Pp. 347403 in: Hydrous Phyllosilicates (Exclusive of Micas) (Bailey, S.W., editor). Reviews in Mineralogy, 19. Mineralogical Society of America, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Bailey, S. W., & Lister, J. (1989). Structures, compositions, and X-ray diffraction identification of dioctahedral chlorites. Clays and Clay Minerals, 37, 193202.CrossRefGoogle Scholar
Bobos, I., Noronha, F., & Mateus, A. (2018). Fe-, Fe,Mn- and Fe,Mgchlorite: A genetic linkage to W, (Cu,Mo) mineralization in the magmatic-hydrothermal system of Borralha, northern Portugal. Mineralogical Magazine, 82, S259–S279.CrossRefGoogle Scholar
Bondi, M., Morten, L., & Rossi, P. L. (1976). Chlorites from Italian granitoid rocks. Tschermaks Mineralogische und Petrographische Mitteilungen, 23, 3950.CrossRefGoogle Scholar
Britvin, S. N., Dolivo-Dobrovolsky, D. V., & Krzhizhanovskaya, M. G. (2017). Software for processing the X-ray powder diffraction data obtained from the curved image plate detector of Rigaku RAXIS Rapid II diffractometer. Zapiski Rossiiskogo Mineralogicheskogo Obshchestva, 146, 104107 (in Russian).Google Scholar
Bruker AXS. (2014) Topas 5.0. General profile and structure analysis software for powder diffraction data. Karlsruhe, Germany.Google Scholar
Chukanov, N. V. (2014). Infrared Spectra of Mineral Species: Extended Library. Dordrecht–Heidelberg–New York–London: Springer-Verlag GmbH.CrossRefGoogle Scholar
Chukhrov, F. V. (Ed.). (1992). Minerals. Moscow: Nauka (in Russian).Google Scholar
Deer, W. A., Howie, R. A., & Zussman, J. (2009). Rock-forming Minerals. Layered Silicates Excluding Micas and Clay Minerals (313 pp). London: The Geological Society.Google Scholar
Durovic, S., Dornberger-Schiff, K., & Weiss, Z. (1983). Chlorite polytypism. I. OD interpretation and polytype symbolism of chlorite structures. Acta Crystallographica, B39, 547552.CrossRefGoogle Scholar
Hey, M. H. (1954). A new review of chlorites. Mineralogical Magazine, 30, 277292.CrossRefGoogle Scholar
Hillier, S., & Velde, B. (1991). Octahedral occupancy and the chemical composition of diagenetic (low-temperature) chlorite. Clay Minerals, 26, 149168.CrossRefGoogle Scholar
Hybler, J. (2014). Refinement of cronstedtite-1M. Acta Crystallograpica, B70, 963972.Google Scholar
Hybler, J. (2016). Crystal structure of cronstedtite-6T2, a non-MDO polytype. European Journal of Mineralogy, 28, 777788.CrossRefGoogle Scholar
Hybler, J., Sejkora, J., & Venclík, V. (2016). Polytypism of cronstedtite from Pohled, Czech Republic. European Journal of Mineralogy, 28, 765775.CrossRefGoogle Scholar
Hybler, J., Števko, M., & Sejkora, J. (2017). Polytypism of cronstedtite from Nižná Slaná, Slovakia. European Journal of Mineralogy, 29, 9199.CrossRefGoogle Scholar
Ivanyuk, G. Y., Yakovenchuk, V. N., & Pakhomovsky, Y. A. (2002). Kovdor (322 pp). Apatity, Russia: Laplandia minerals.Google Scholar
Libowitzky, E. (1999). Correlation of O–H stretching frequencies and O–H · · · O hydrogen bond lengths in minerals. Monatshefte für Chemie, 130, 10471059.CrossRefGoogle Scholar
Liebau, F. (1985). Structural Chemistry of Silicates (354 pp). Berlin–Heidelberg: Springer-Verlag.CrossRefGoogle Scholar
López-Munguira, A., Nieto, F., & Morata, D. (2002). Chlorite composition and geothermometry: a comparative HRTEM/AEM-EMPA-XRD study of Cambrian basic lavas from the Ossa Morena Zone, SW Spain. Clay Minerals, 37, 267281.CrossRefGoogle Scholar
Pignatelli, I., Mugnaioli, E., & Marrocchi, Y. (2018). Cronstedtite polytypes in the Paris meteorite. European Journal of Mineralogy, 30, 349354.CrossRefGoogle Scholar
Prieto, A. C., Dubessy, A. C., & Cathelineau, M. (1991). Structure–composition relationships in trioctahedral chlorites: A vibrational spectroscopy study. Clays and Clay Minerals, 39, 531539.CrossRefGoogle Scholar
Shikazono, N., & Kawahata, H. (1987). Compositional differences in chlorite from hydrothermally altered rocks and hydrothermal ore deposits. The Canadian Mineralogist, 25, 465474.Google Scholar
Strakhov, N. M. (Ed.). (1966). Kerch Iron-ore Basin. Moscow: Nedra 576 pp. (in Russian).Google Scholar
Tang, D., Shi, X., Jiang, G., Zhou, X., & Shi, Q. (2017). Ferruginous seawater facilitates the transformation of glauconite to chamosite: An example from the Mesoproterozoic Xiamaling formation of North China. American Mineralogist, 102, 23172332.CrossRefGoogle Scholar
Wahle, M. W., Bujnowski, T. J., Guggenheim, S., & Kogure, T. (2010). Guidottiite, the Mn-analogue of cronstedtite: A new serpentine group mineral from South Africa. Clays and Clay Minerals, 58, 364378.CrossRefGoogle Scholar
Wu, D., Pan, J., Xia, F., Huang, G., & Lai, J. (2019). The mineral chemistry of chlorites and its relationship with uranium mineralization from huangsha uranium mining area in the middle Nanling Range, SE China. Minerals, 9, 199, 23 pp. Scholar
Zanazzi, P. F., Comodi, P., Nazzareni, S., & Andreozzi, G. B. (2009). Thermal behaviour of chlorite: an in-situ single-crystal and powder diffraction study. European Journal of Mineralogy, 21, 581589.CrossRefGoogle Scholar
Zane, A., & Sassi, R. (1998). New data on metamorphic chlorite as a petrogenetic indicator mineral, with special regard to greenschistfacies rocks. The Canadian Mineralogist, 36, 713726.Google Scholar
Supplementary material: File

Chukanov et al. supplementary material
Download undefined(File)
File 132.4 KB