|
|
|
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
1 Dipartimento di Scienze della Terra, Università di Milano, I-20133 Milano, Italy
2 Institut für Geowissenschaften, Christian-Albrechts-Universität, D-24098 Kiel, Germany
Correspondence: * E-mail: artioli{at}iummix.terra.unimi.it
The crystal structure of julgoldite-Fe3+ from Bombay, India, was investigated by 57Fe Mössbauer spectroscopy and synchrotron X-ray powder diffraction. Only ferric iron was detected in the Mössbauer measurements and it occurs at two different octahedral sites in the atomic ratio 20:80. Based on Rietveld refinements, the Fe3+ cations are located at the X- and Y-octahedral sites with atomic percentages of about 25% and 75%, respectively. The resulting chemical formula of the Bombay julgoldite sample is Ca8(Fe2.73+Al1.1Mg0.2)(Fe8.03+)Si12O42(OH)14. The oxidation state of Fe is not the same as that arrived at through simple crystal-chemical considerations. Such analysis cannot give quantitative results for the valence state of mixed-valence cations in pumpellyite-type minerals and their intracrystalline partitioning behavior. Assignments of the Mössbauer absorption doublets and an analysis of Fe-intracrystalline partitioning behavior are discussed with reference to previous works on different pumpellyite-type minerals.
This article has been cited by other articles:
![]() |
M. Nagashima, N.-S. Rahmoun, E. V. Alekseev, C. A. Geiger, T. Armbruster, and M. Akasaka Crystal chemistry of macfallite: Relationships to sursassite and pumpellyite American Mineralogist, November 1, 2008; 93(11-12): 1851 - 1857. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Nagashima and M. Akasaka THE DISTRIBUTION OF CHROMIUM IN CHROMIAN PUMPELLYITE FROM SARANI, URALS, RUSSIA: A TOF NEUTRON AND X-RAY RIETVELD STUDY Can Mineral, August 1, 2007; 45(4): 837 - 846. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. Hatert, M. Pasero, N. Perchiazzi, and T. Theye Pumpellyite-(Al), a new mineral from Bertrix, Belgian Ardennes European Journal of Mineralogy, March 1, 2007; 19(2): 247 - 253. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. F. Brigatti, E. Caprilli, and M. Marchesini Poppiite, the V3+ end-member of the pumpellyite group: Description and crystal structure American Mineralogist, April 1, 2006; 91(4): 584 - 588. [Abstract] [Full Text] [PDF] |
||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |