|
|
 |
|||||||||||||||||
|
|||||||||||||||||
 |
|||||||||||||||||
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Department of Geological Sciences, Box 351310, University of Washington, Seattle, WA 98195/1310, USA
* E-mail: chukchi{at}u.washington.edu
We have developed a cluster variation method (CVM) model based on cuboctahedral and octahedral basis clusters containing 13 and 6 atoms, respectively, and applied it to the analysis of the thermodynamic mixing properties of (Zn,Fe)S solid solutions. The model, in which the internal energy of the lattice is approximated by next to nearest neighbour (nnn) pair interactions and many-body interactions associated with nearest neighbour (nn) equilateral triangles, describes the FeS contents of sphalerites equilibrated with pyrrhotite and pyrite, and with pyrrhotite and iron metal within experimental uncertainties. The model predicts moderate deviations from ideality; the mean values of the Lewis and Randall activity coefficient of FeS and ZnS are, 1.48 and 1.03, respectively. Predictions of the model are in qualitative agreement with cell-edge data. The model also predicts that sphalerites undergo long-range ordering to lower-symmetry structures at temperatures only slightly below those investigated experimentally, a result in agreement with inferences from an existing Mössbauer investigation of synthetic sphalerites.
More realistic models in which interactions are ascribed to larger species (nn triangular and centred square species) predict that such long-range ordering occurs at even higher temperatures and underscore the need for better characterization of the structures of (Zn,Fe)S minerals.
KEYWORDS: sphalerite, thermodynamics, cluster variation method, pyrrhotite, pyrite
This article has been cited by other articles:
|
|
 |
|
  A. Pring, S. C. Tarantino, C. Tenailleau, B. Etschmann, M. A. Carpenter, M. Zhang, Y. Liu, and R. L. Withers The crystal chemistry of Fe-bearing sphalerites: An infrared spectroscopic study American Mineralogist, April 1, 2008; 93(4): 591 - 597. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. O. Sack and D. S. Ebel Thermochemistry of Sulfide Mineral Solutions Reviews in Mineralogy and Geochemistry, January 1, 2006; 61(1): 265 - 364. [Full Text] [PDF]
|
|
|
|
|
|
M. E. Fleet Phase Equilibria at High Temperatures Reviews in Mineralogy and Geochemistry, January 1, 2006; 61(1): 365 - 419. [Full Text] [PDF]
|
|
|
|
|
|
F. Di Benedetto, G. P. Bernardini, P. Costagliola, D. Plant, and D. J. Vaughan Compositional zoning in sphalerite crystals American Mineralogist, August 1, 2005; 90(8-9): 1384 - 1392. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. O. Sack, R. Fredericks, L. S. Hardy, and D. S. Ebel Origin of high-Ag fahlores from the Galena Mine, Wallace, Idaho, U.S.A. American Mineralogist, May 1, 2005; 90(5-6): 1000 - 1007. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. O. Sack, R. O. Sack, J. V. G. Lynch, and F. Foit Jr. Fahlore as a petrogenetic indicator: Keno Hill Ag-Pb-Zn District, Yukon, Canada Mineralogical Magazine, October 1, 2003; 67(5): 1023 - 1038. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. O. Sack NOTE ON "LARGE-SCALE HYDROTHERMAL ZONING REFLECTED IN THE TETRAHEDRITE FREIBERGITE SOLID SOLUTION, KENO HILL Ag Pb Zn DISTRICT, YUKON" BY J.V. GREGORY LYNCH Can Mineral, December 1, 2002; 40(6): 1717 - 1719. [Full Text] [PDF]
|
|
|
|
|
|
R. O. Sack and P. C. Goodell Retrograde reactions involving galena and Ag-sulphosalts in a zoned ore deposit, Julcani, Peru Mineralogical Magazine, December 1, 2002; 66(6): 1043 - 1062. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. O. Sack, S. M. Kuehner, and L. S. Hardy Retrograde Ag-enrichment in fahlores from the Coeur d'Alene mining district, Idaho, USA Mineralogical Magazine, February 1, 2002; 66(1): 215 - 229. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Bosenick, M. T. Dove, E. R. Myers, E. J. Palin, C. I. Sainz-Diaz, B. S. Guiton, M. C. Warren, M. S. Craig, and S. A. T. Redfern Computational methods for the study of energies of cation distributions: applications to cation-ordering phase transitions and solid solutions Mineralogical Magazine, April 1, 2001; 65(2): 193 - 219. [Abstract] [Full Text] [PDF]
|
|
| JOURNAL HOME | HELP | CONTACT PUBLISHER | SUBSCRIBE | ARCHIVE | SEARCH | TABLE OF CONTENTS |
