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Pyrochlore Supergroup
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Hydrokenoelsmoreite
Clara Mine, Rankach valley, Oberwolfach, Wolfach, Black Forest, Baden-Württemberg, Germany
© Stephan Wolfsried
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| A typically is a large [8]-coordinated cation with a radius of ~1.0 Å or a vacancy (□), but can also be H2O. The A site therefore may host Na, Ca, Sr, Pb2+, Sn2+, Sb3+, Y, U, □, or H2O or, less frequently Ag, Mn, Ba, Fe2+, Bi3+, Ce (and other REE), Sc or Th · D is a [6]-coordinated cation typically of high field-strength. This site thus may contain Ta, Nb, Ti, Sb5+ or W, but also V5+, Sn4+, Zr, Hf, Fe3+, Mg, Al and Si X typically is O, but can include subordinate OH and F Z typically is an anion, but can also be a vacancy, H2O, or a very large (>> 1.0 Å) monovalent cation (site 8b). Examples are OH–, F, O, □, H2O, K, Cs, Rb. The symbols m, w, and n represent parameters that indicate incomplete occupancy of the A, X and Z sites, respectively. Vacancies have not been found to occur at the D site | ||||||||||||||||||||
A group of chemically complex cubic oxides.
A correct identification of individual members is only possible using a combination of several analytical methods.
The nomenclature was recently revised by Atencio et al. (2010); see also Christy & Atencio (2013).
Classification of Pyrochlore Supergroup | |||||||||||||||||||||||||||||||||||||
| mindat.org URL: | http://www.mindat.org/min-29175.html Please feel free to link to this page. | ||||||||||||||||||||||||||||||||||||
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Chemical Properties of Pyrochlore Supergroup | |||||||||||||||||||||||||||||||||||||
| Formula: |
A typically is a large [8]-coordinated cation with a radius of ~1.0 Å or a vacancy (□), but can also be H2O. The A site therefore may host Na, Ca, Sr, Pb2+, Sn2+, Sb3+, Y, U, □, or H2O or, less frequently Ag, Mn, Ba, Fe2+, Bi3+, Ce (and other REE), Sc or Th · D is a [6]-coordinated cation typically of high field-strength. This site thus may contain Ta, Nb, Ti, Sb5+ or W, but also V5+, Sn4+, Zr, Hf, Fe3+, Mg, Al and Si X typically is O, but can include subordinate OH and F Z typically is an anion, but can also be a vacancy, H2O, or a very large (>> 1.0 Å) monovalent cation (site 8b). Examples are OH–, F, O, □, H2O, K, Cs, Rb. The symbols m, w, and n represent parameters that indicate incomplete occupancy of the A, X and Z sites, respectively. Vacancies have not been found to occur at the D site | ||||||||||||||||||||||||||||||||||||
Relationship of Pyrochlore Supergroup to other Species | |||||||||||||||||||||||||||||||||||||
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Other Names for Pyrochlore Supergroup | |||||||||||||||||||||||||||||||||||||
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Other Information | |||||||||||||||||||||||||||||||||||||
| Health Warning: | No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care. | ||||||||||||||||||||||||||||||||||||
References for Pyrochlore Supergroup | |||||||||||||||||||||||||||||||||||||
| Reference List: - + | Pyatenko, Y.A. (1959) Crystal chemistry and characteristics of minerals of pyrochlore group. Kristallografiya: 4: 204-208 (English abstract). Hogarth, D.D. (1977) Classification and nomenclature of the pyrochlore group. American Mineralogist: 62: 403-410. Chakoumakos, B.C. (1984) Systematics of the pyrochlore structure type, ideal A2B2X6Y. Journal of Solid State Chemistry: 53: 120-129. Greegor, R.B., Lytle, F.W., Chakoumakos, B.C., Lumpkin, G.R., and Ewing, R.C. (1985) An investigation of metamict and annealed pyrochlores by X-ray absorption spectroscopy. In C.M. jantzen, J.A. Stone, and R.C. Ewing, Eds., Scientific Basis for Nuclear Waste Management VIII: 655-662. Materials Research Society, Pittsburgh. Lumpkin, G.R., Foltyn, E.M., and Ewing, R.C. (1986) Thermal recrystallization of alpha-recoil damaged minerals of the pyrochlore structure type. Journal of Nuclear Materials: 139: 113-120. Lumpkin, G.R. and Ewing, R.C. (1988) Alpha-decay damage in minerals of the pyrochlore group. Physics and Chemistry of Minerals: 16: 220. Lumpkin, G.R. and Ewing, R.C. (1992) Geochemical alteration of pyrochlore group minerals: Microlite subgroup. American Mineralogist: 77: 179-188. Johan, V. and Johan, Z. (1994) Accessory minerals of the Cinovec (Zinnwald) granite cupola, Czech Republic Part 1: Nb-, Ta-, and Ti-bearing oxides. Mineralogy and Petrology: 51: 323-343. Lumpkin, G.R. and Ewing, R.C. (1995) Geochemical alteration of pyrochlore group minerals: Pyrochlore subgroup. American Mineralogist: 80: 732-743. Lumpkin, G.R. and Ewing, R.C. (1996) Geochemical alteration of pyrochlore group minerals: Betafite subgroup. American Mineralogist: 81: 1237-1248. Hogarth, D.D., Williams, C.T., and Jones, P. (2000) Primary zoning in pyrochlore group minerals from carbonatites. Mineralogical Magazine: 64: 683-697. Nasraoui, M. and Waerenborgh, J.C. (2001) Fe speciation in weathered pyrochlore-group minerals from the Lueshe and Araxá (Barreiro) carbonatites by 57Fe Mössbauer spectroscopy. Canadian Mineralogist: 39: 1073-1080. Chakhmouradian, A.R. and Mitchell, R.H. (2002) New data on pyrochlore- and perovskite-group minerals from the Lovozero alkaline complex, Russia. European Journal of Mineralogy: 14: 821-836. Atencio D., Andrade M.B., Christy A.G., Giere R., Kartashov P.M. (2010): The pyrochlore supergroup of minerals: nomenclature. Canadian Mineralogist, 48, 569-594. Christy, A. G. and Atencio, D. (2013): Clarification of status of species in the pyrochlore supergroup. Mineralogical Magazine, 77, 13-20. | ||||||||||||||||||||||||||||||||||||
Internet Links for Pyrochlore Supergroup | |||||||||||||||||||||||||||||||||||||
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Localities for Pyrochlore Supergroup | |||||||||||||||||||||||||||||||||||||
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The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the
 symbol to view information about a locality.
The symbol next to localities in the list
can be used to jump to that position on the map.
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