Current Problems with the Nomenclature of Phyllosilicates*

B. B. Zvyagin
Institute of Ore Mineralogy (IGEM), Russian Academy of Sciences, Staromonetny 35, 109017 Moscow, Russia
* This paper is based on the presentation by B. B. Zvyagin during the award of the 2000 Marilyn and Sturgess W. Bailey Distinguished Member Award of the Clay Minerals Society. E-mail of corresponding author: zvyagin@genome.eimb.relarn.ru

Abstract: The nomenclature of phyllosilicates is discussed in relation to structural variations of layers and interlayers. Some discrepancies in the nomenclature which arose due to historical reasons and different viewpoints may be reconciled if the choice of the construction units (layers or their parts) is related to definite sets of structures for which these units are common. Features of idealized models approximating real structures should be considered for classification and derivation of nomenclature sets, whereas priority is given to structural variations before lattice and symmetry characteristics. Layer polymorphs, pseudo-polytypes, polytypes (both simple and complex), and OD structures are distinguished. Particular results obtained for micas as a model example of phyllosilicates in relation to modular structures in general are considered in an Appendix.

Key Words: Construction Unit • Nomenclature • Phyllosilicates

Clays and Clay Minerals; December 2001 v. 49; no. 6; p. 492-499; DOI: 10.1346/CCMN.2001.0490602
© 2001, The Clay Minerals Society
Clay Minerals Society (www.clays.org)