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Verbeekite, monoclinic PdSe2, a new mineral from the Musonoi Cu-Co-Mn-U mine, near Kolwezi, Shaba Province, Democratic Republic of Congo

Published online by Cambridge University Press:  05 July 2018

A. C. Roberts*
Affiliation:
Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario K1A 0E8, Canada
W. H. Paar
Affiliation:
Institut für Mineralogie der Universität, Hellbrunnerstr. 34, A-5020 Salzburg, Austria
M. A. Cooper
Affiliation:
Department of Geological Sciences, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
D. Topa
Affiliation:
Institut für Mineralogie der Universität, Hellbrunnerstr. 34, A-5020 Salzburg, Austria
A. J. Criddle
Affiliation:
Department of Mineralogy, The Natural History Museum, Cromwell Road, London SW7 5BD, UK
J. Jedwab
Affiliation:
Laboratoire de Géochimie et de Mineralogie, CP160/02 - Université Libre de Bruxelles, 50, Avenue Roosevelt, B-1050 Bruxelles, Belgium
*

Abstract

Verbeekite, ideally PdSe2, monoclinic with space-group choices C2/m, C2 or Cm; a = 6.659(7), b = 4.124(5), c = 4.438(6) Å, ß = 92.76(3)°, V = 121.7(4) Å3; a:b:c = 1.6147:1:1.0761, Z = 2, is a new, very rare, primary mineral, intimately associated with secondary oosterboschite {(Pd,Cu)7Se5}, from the Musonoi Cu-Co-Mn-U mine, near Kolwezi, Shaba Province, Democratic Republic of Congo. Additional associated minerals are Cu- and Pd-bearing trogtalite {(Co,Cu,Pd)Se2}, Se-bearing digenite and Se-bearing covellite. The strongest five lines of the X-ray powder-diffraction pattern {d in Å (I) (hkl)} are: 4.423(30)(001), 3.496 (30)(110), 2.718(100)(111), 1.955(50)(310 and 1.896(50)(12). The mineral has also been identified, as a single anhedral 25 µm-sized grain, from Hope's Nose, Torquay, Devon, England where it is associated with native gold, chrisstanleyite Ag2Pd3Se4, oosterboschite(?), unnamed Pd2HgSe3 and cerussite. At Musonoi, altered verbeekite grains do not exceed 200 µm in size and are anhedral, black, with a black streak and a metallic lustre. The mineral is opaque, brittle, has an uneven fracture, and lacks discernible cleavage. The VHN5 ranges 490–610, mean 550 kp/mm2 (2 indentations), roughly approximating a Mohs' hardness of 5Ý. Dcalc. = 7.211 g/cm3 for the ideal formula. Electron-microprobe analyses (mean of 4 spot analyses) yielded Pd 39.6, Cu 0.5, Se 58.8, total 98.9 wt.%. The empirical formula is (Pd0.99Cu0.02)σ1.01Se1.99, based on Pd+Cu+Se = 3. In plane-polarized reflected light, the mineral is a nondescript grey and is neither pleochroic nor perceptibly bireflectant. Anisotropy is moderate with rotation tints in varying shades of brown. Reflectance spectra and colour values are tabulated. The name honours Dr Théodore Verbeek (1927–1991) who was the first geoscientist to study the Musonoi palladium mineralization in the Democratic Republic of Congo (1955–1967) and who co-discovered this new mineral phase.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2002

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References

Cesbron, F., Bachet, B. and Oosterbosch, R. (1965) La demesmaekerite, sélénite hydraté d'uranium, cuivre et plomb. Bulletin de la Societé française Minéralogie et Cristallographie, 88, 422425.CrossRefGoogle Scholar
Cesbron, F. Oosterbosch, R. and Pierrot, R. (1969) Une nouvelle espce minérale: la marthozite. Uranyl-sélénite de cuivre hydraté. Bulletin de la Societé française Minéralogie et Cristallographie, 92, 278283.CrossRefGoogle Scholar
Cesbron, F. Pierrot, R. and Verbeek, T. (1971) La derriksite, Cu4(UO2)(SeO3)2(OH)6˙H2O, une nou-velle espéce minérale. Bulletin de la Societé française Minéralogie et Cristallographie, 94, 534537.CrossRefGoogle Scholar
Criddle, A.J. (1980) Editorial policy for the second issue of the IMA/COM Quantitative Data File. The Canadian Mineralogist, 18, 553558.Google Scholar
Demesmaeker, G., François, A. and Oosterbosch, R. (1963) La tectonique des gisements cupriféres stratiformes du Katanga. Pp. 47115 in: Stratiform Copper Deposits in Africa Part 2 – Tectonics. (Lombard, J. and Nicolini, P., editors). Association of African Geological Surveys, Paris.Google Scholar
François, A. (1987) Synthse géologique sur l'Arc cuprifre du Shaba (Rép. du Zaïre). Societé Belge de Géologie, Vol. hors-série. Centenaire 1987, 1564.Google Scholar
Gauthier, G. François, A.. Deliens, M. and Piret, P. (1989) Famous mineral localities: The uranium deposits of the Shaba Region, Zaïre. Mineralogical Record, 20, 265288, 304.Google Scholar
Grłnvold, F. and Rł st, E. (1957) The Crystal Structure of PdSe2 and PdS2 . Acta Crystallographica, 10, 329331.CrossRefGoogle Scholar
Henry, N.F.M. (1980) IMA/COM Report on Symbols and Definitions. The Canadian Mineralogist, 18, 549551.Google Scholar
Jedwab, J. (1997) Minéralogie des Métaux du Groupe du Platine au Shaba, Zaï. Pp. 325355 in: Centenaire des premiéres études sur la géologie shabienne (Zaï): Gisements de cuivre stratiformes et minéralisations associée. (Charlet, J.M., editor). Faculté Polytechnique Mons et Academie Royale des Sciences d'Outremer.Google Scholar
Johan, Z., Picot, P., Pierrot, R. and Verbeek, T. (1970) L'oosterboschite (Pd, Cu)7Se5, une nouvelle espce minérale et la trogtalite cupro-palladifre de Musonoï (Katanga). Bulletin de la Societé française Minéralogie et Cristallographie, 93, 476481.CrossRefGoogle Scholar
Oosterbosch, R. (1962) Les minéralisations dans le systéme de Roan au Katanga, Pp. 71136 in: Stratiform Copper Deposits in Africa, Part 1 – Lithology, Sedimentology. (Lombard, J. and Nicolini, P., editors). Association of African Geological Surveys, Paris.Google Scholar
Paar, W.H., Roberts, A.C, Criddle, A.J. and Topa, D. (1998) A new mineral, chrisstanleyite, Ag2Pd3Se4, from Hope's Nose, Torquay, Devon, England. Mineralogical Magazine, 62, 257264.CrossRefGoogle Scholar
Pierrot, R. Toussaint, J. and Verbeek, T. (1965) La guilleminite, une nouvelle espce minérale. Bulletin de la Societé française Minéralogie et Cristallographie, 88, 132135.CrossRefGoogle Scholar