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The solid solution between platinum and palladium in nature

Published online by Cambridge University Press:  05 July 2018

L. Bindi*
Affiliation:
Dipartimento di Scienze della Terra, Università degli Studi di Firenze, via La Pira 4, I-50121 Firenze, Italy
F. Zaccarini
Affiliation:
Department of Applied Geosciences and Geophysics, University of Leoben, Peter Tunner str. 5, A-8700 Leoben, Austria
G. Garuti
Affiliation:
Department of Applied Geosciences and Geophysics, University of Leoben, Peter Tunner str. 5, A-8700 Leoben, Austria
N. Angeli
Affiliation:
UNESP-IGCE, Departamento de Petrologia e Metalogenia, Universidade Estadual Paulista, Av. 24-A, nº 1515, 13506-900, Rio Claro 13500, SP, Brazil
*

Abstract

Chemical and structural data are reported for platinum–palladium intermediates from two nuggets found at Córrego Bom Sucesso, Minas Gerais, Brazil. Three grains with simple stoichiometries (i.e. PtxPd1−x with x ∼0.67, ∼0.5 and ∼0.33, which correspond to Pt2Pd, PtPd and PtPd2, respectively) were characterized by single-crystal X-ray diffraction and electron-probe microanalysis. In the absence of single-crystal data it might be tempting to hypothesize that such simple stoichiometries represent distinct mineral species, however structural analyses show that all of the phases are cubic and crystallize in space group Fmm. They are, therefore, natural intermediates in the palladium–platinum solid solution. Reflectance and micro-hardness values are reported for the samples and a comparison with the pure metallic elements made. On the basis of information gained from the chemical and structural characterization it can be concluded that there is a complete solid solution between Pt and Pd in nature. These findings corroborate results from experiments on synthetic compounds.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

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References

Angeli, N. (2005) Platinum group minerals in Eastern Brazil, geology and occurrences in chromitite and placers. Platinum Metals Review, 49, 4153.CrossRefGoogle Scholar
Bhardwaj, S.R., Kerkar, A.S., Tripathi, S.N. and Dharwadkar, S.R. (1991) The palladium–platinum phase diagram. Journal of Less Common Metals, 169, 167172.CrossRefGoogle Scholar
Cabral, A.R., Beaudoin, G., Kwitko-Ribeiro, R., Lehmann, B., Poloˆnia, J.C. and Choquette, M. (2006) Platinum–palladium nuggets and mercuryrich palladiferous platinum from Sero, Minas Gerais. The Canadian Mineralogist, 44, 385397.CrossRefGoogle Scholar
Cabral, A.R., Lehmann, B., Tupinambá, M., Schlosser, S., Kwitko-Ribeiro, R. and de Abreu, F.R. (2009a) The platiniferous Au-Pd belt of Minas Gerais, Brazil, and genesis of its botryoidal Pt-Pd aggregates. Economic Geology, 104, 12651276.CrossRefGoogle Scholar
Cabral, A.R., Vymazalová , A., Lehmann, B., Tupinambá, M., Haloda, J., Laufek, F., Vlcek, V. and Kwitko-Ribeiro, R. (2009b) Poorly crystalline Pd-Hg-Au intermetallic compounds from Co´rrego Bom Sucesso, southern Serra de Espinhaco, Brazil. European Journal of Mineralogy, 21, 811816.CrossRefGoogle Scholar
Cabri, L.J. and Feather, C.E. (1975) Platinum-iron alloys: a nomenclature based on a study of natural and synthetic alloys. Canadian Mineralogist, 13, 117126.Google Scholar
Cabri, L.J., Stewart, J.M., Laflamme, J.H.G. and Szymanski J.T. (1977) Platinum-group minerals from Onverwacht. III. Genkinite, (Pt,Pd)4Sb3, a new mineral. The Canadian Mineralogist, 15, 389392.Google Scholar
Cassedanne, J.P., Jedwab, J. and Alves, J.N. (1996) Apport d’une prospection systématique a` l’étude de l’origine de l’or et du platine alluviaux du Co´rrego Bom Sucesso (Serro – Minas Gerais). Anais da Academia Brasileira de Cieˆncias, 68, 569582.Google Scholar
Fedortchouk, Y., LeBarge, W., Barkov, A.Y., Fedele, L., Bodnar, R.J. and Martin, R.F. (2010) Platinum-group minerals from a placer deposit in Burwash Creek, Kluane area, Yukon Territory, Canada. The Canadian Mineralogist, 48, 583596.CrossRefGoogle Scholar
Fleet, M.E., de Almeida, C.M. and Angeli, N. (2002) Botryoidal platinum, palladium and potarite from the Bom Sucesso stream, Minas Gerais, Brazil: compositional zoning and origin. The Canadian Mineralogist, 40, 341355.CrossRefGoogle Scholar
Garuti, G., Proenza, J.A. and Zaccarini, F. (2007) Distribution and mineralogy of platinum-group elements in altered chromitites of the Campo Formoso layered intrusion (Bahia State, Brazil): control by magmatic and hydrothermal processes. Mineralogy and Petrology, 86, 159188.CrossRefGoogle Scholar
Garuti, G., Zaccarini, F., Proenza, J.A., Thalhammer O.A.R. and Angeli, N. (2012) Platinum-group minerals in chromitites of the Niquelaˆndia layered intrusion (Central Goiás, Brazil): their magmatic origin and low-temperature reworking during serpentinization and lateritic weathering. Minerals, 2, 365384.CrossRefGoogle Scholar
Genkin, A.D., Zhuravlev, N.N. and Smirnova E.M. (1963) Moncheite and kotulskite, new minerals; and the composition of michenerite. Zapiski Vsesoyuznogo Mineralogicheskogo Obshchvestva, 92, 3350. [in Russian].Google Scholar
Hawley, J.E. and Berry, L.G. (1958) Michenerite and froodite, palladium bismuth minerals. The Canadian Mineralogist, 6, 200209.Google Scholar
Hussak, E. (1906) O´ palládio e a platina do Brasil. Annaes Escola de Minas de Ouro Preto, 8, 75188.Google Scholar
Kingston, G.A. (1966) The occurrence of platinoid bismuthotellurides in the Merensky Reef at Rustenburg platinum mine in the Western Bushveld. Mineralogical Magazine, 35, 815834.CrossRefGoogle Scholar
Mihalik, P., Hiemstra, S.A. and De Villieps, J.P.R. (1975) Rustenburgite and atokite, two new platinumgroup minerals from the Merensky Reef, Bushveld igneous complex. The Canadian Mineralogist, 13, 146150.Google Scholar
Nickel, E.H. and Grice, J.D. (1998) The IMA Commission on New Minerals and Mineral Names: procedures and guidelines on mineral nomenclature, 1998. The Canadian Mineralogist, 36, 913926.Google Scholar
Stumpfl, E.F. and Tarkian, L. (1974) Vincentite, a new palladium mineral from South-East Borneo. Mineralogical Magazine, 39, 525527.CrossRefGoogle Scholar
Wollaston, W.H. (1805) On the discovery of palladium; with observations on other substances, found with platina. Philosophical Transactions of the Royal Society of London, 95, 316330.Google Scholar