Quick
Search: 		  
advanced search
 GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help 
European Journal of Mineralogy Signup for GSW Email News
JOURNAL HOME HELP FEEDBACK/COMMNET SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
European Journal of Mineralogy; May, June 2005; v. 17; no. 3; p. 475-481; DOI: 10.1127/0935-1221/2005/0017-0475
© 2005 E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (3)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by BRIGATTI, M. F.
Right arrow Articles by POPPI, L.
Right arrow Search for Related Content
GeoRef
Right arrow GeoRef Citation

Articles

Crystal structure and chemistry of trilithionite-2M2 and polylithionite-2M2

Maria Franca BRIGATTI1,*, Enrico CAPRILLI1, Daniele MALFERRARI1, Luca MEDICI2 and Luciano POPPI1

1 Dipartimento di Scienze della Terra dell'Università di Modena e Reggio Emilia, Via S. Eufemia 19, I-41100 Modena, Italy
2 CNR – Istituto di Metodologie per l'Analisi Ambientale, C.da S. Loja, I-85050 - Tito Scalo (PZ), Italy

* E-mail: brigatti{at}unimore.it

The crystal chemistry of three Li-bearing mica-2M2 crystals from pegmatites has been studied by chemical analyses and single crystal X-ray diffraction; their belonging to the trilithionite-polylithionite join is highlighted by the following compositional ranges in atoms per formula unit [based on O12-(x+y) (OH)xFy]: 3.198 ≤ Si ≤ 3.538, 0.462 ≤ [IV]Al ≤ 0.811, 1.195 ≤ [VI]Al ≤ 1.390, 0.031 ≤ (Fe+Mn) ≤ 0.072, 1.522 ≤ Li ≤ 1.757, 0.872 ≤ K ≤ 0.906, 0.030 ≤ Na ≤ 0.073, 0.000 ≤ (Cs+Rb) ≤ 0.099, 1.541 ≤ F ≤ 1.722. The correlation between F and Li content is confirmed, as observed in Li-rich micas.

Crystal structure refinements were carried out in space group C2/c (R values vary between 0.030 and 0.031). The crystal chemistry is mostly influenced by tetrahedral chemical composition. Increasing [IV]Al content, {alpha} and {psi}M1 parameters increase; Si content involves a lowering of the interlayer separation and tetrahedral thickness. Li content affects octahedral thickness. The stability of 2M2 polytype seems to be induced by a relative increase of {Delta}z tetrahedral parameter, which reduces the repulsion between basal tetrahedral oxygen atoms. Unlike Li-bearing muscovite, trioctahedral Li-bearing mica crystals show an octahedral occupancy not related to octahedral charge.

Key-words: mica, trilithionite, polylithionite, lithium, 2M2 polytype.




This article has been cited by other articles:


Home page
 Clays and Clay MineralsHome page
T. Kogure, J. Kameda, and V. A. Drits
STACKING FAULTS WITH 180{degrees} LAYER ROTATION IN CELADONITE, AN Fe- AND Mg-RICH DIOCTAHEDRAL MICA
Clays and Clay Minerals, December 1, 2008; 56(6): 612 - 621.
[Abstract] [Full Text] [PDF]

Home page
 Clays and Clay MineralsHome page
J. Kameda, R. Miyawaki, V. A. Drits, and T. Kogure
POLYTYPE AND MORPHOLOGICAL ANALYSES OF GUMBELITE, A FIBROUS Mg-RICH ILLITE
Clays and Clay Minerals, October 1, 2007; 55(5): 453 - 466.
[Abstract] [Full Text] [PDF]


JOURNAL HOME HELP FEEDBACK/COMMNET SUBSCRIBE ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 2009 by E. Schweizerbart'sche Verlagsbuchhandlung Science Publishers