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Skaergaardite, PdCu, a new platinum-group intermetallic mineral from the Skaergaard intrusion, Greenland

Published online by Cambridge University Press:  05 July 2018

N. S. Rudashevsky ,
A. M. McDonald ,
L. J. Cabri ,
T. F. D. Nielsen ,
C. J. Stanley ,
Yu. L. Kretzer  and
V. N. Rudashevsky
N. S. Rudashevsky*
Affiliation:
Centre for New Technologies, Svetlanovsky ave., 75-41, St. Petersburg, 195427, Russia
A. M. McDonald
Affiliation:
Department of Earth Sciences, Laurentian University, Ramsy Lake Road, Sudbury, Ontario, Canada
L. J. Cabri
Affiliation:
Cabri Consulting Inc., 99, Fifth Avenue, Suite 122, Ottawa, Ontario, Canada K1S 5P5 CANMET/MMSL, Ottawa, Canada K1A 0G1
T. F. D. Nielsen
Affiliation:
Geological Survey of Denmark and Greenland, Øster Voldgade 10, DK-1350 Copenhagen K, Denmark
C. J. Stanley
Affiliation:
The Natural History Museum, Cromwell Road, London SW7 5BD, UK
Yu. L. Kretzer
Affiliation:
Centre for New Technologies, Svetlanovsky ave., 75-41, St. Petersburg, 195427, Russia
V. N. Rudashevsky
Affiliation:
Centre for New Technologies, Svetlanovsky ave., 75-41, St. Petersburg, 195427, Russia
*
*E-mail: rudash@online.ru
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Abstract

Skaergaardite, PdCu, is a new mineral discovered in the Skaergaard intrusion, Kangerdlugssuaq area, East Greenland. It occurs in a tholeitiic gabbro associated with plagioclase, clinopyroxene, orthopyroxene, ilmenite, titanian magnetite, fayalite and accessory chlorite-group minerals, ferrosaponite, a member of the annite–phlogopite series, hornblende, actinolite, epidote, calcite, ankerite, apatite and baddeleyite. The mineral is found in composite microglobules composed of bornite, chalcocite, digenite, chalcopyrite, with rare cobalt pentlandite, cobaltoan pentlandite, sphalerite, keithconnite, vasilite, zvyagintsevite, (Cu,Pd,Au) and Pt-Fe-Cu-Pd alloys, unnamed PdCu3, (Pd,Cu,Sn), Au3Cu and PdAuCu. Skaergaardite occurs as droplets, equant grains with rounded outlines, subhedral to euhedral crystals and as irregular grains that vary in size from 2 to 75 μm, averaging 22 μm. It is steel grey with a bronze tint, has a black streak, a metallic lustre and is sectile. Neither cleavage nor fracture was observed. The mineral has a micro-indentation hardness of VHN25 = 257. It is isotropic, non-pleochroic and exhibits neither discernible internal reflections nor evidence of twinning. Skaergaardite varies from bright creamy white (associated with bornite and chalcopyrite) to bright white (associated with digenite and chalcocite). Reflectance values in air (and in oil) are: 58.65 (47.4) at 470 nm, 62.6 (51.1) at 546 nm, 64.1 (52.8) at 589 nm and 65.25 (53.95) at 650 nm. The average of 311 electron-microprobe analyses gives: Pd 58.94, Pt 1.12, Au 2.23, Cu 29.84, Fe 3.85, Zn 1.46, Sn 1.08, Te 0.28 and Pb 0.39, total 99.19 wt.%, corresponding to (Pd0.967Au0.020Pt0.010)Σ0.997(Cu0.820Fe0.120 Zn0.039Sn0.016Te0.004Pb0.003)Σ1.002. The mineral is cubic, space group Pm3m, a = 3.0014(2) Å, V = 27.0378 Å3, Z = 1. Dcalc is 10.64 g/cm3. The six strongest lines in the X-ray powder-diffraction pattern [d in Å (I)(hkl)] are: 2.122(100)(110), 1.5000(20)(200), 1.2254(50)(211), 0.9491(20)(310), 0.8666(10)(222), 0.8021(70)(321). The mineral has the CsCl-type structure. It is believed to be isostructural with wairauite (CoFe), synthetic CuZn (β-brass) and is structurally related to hongshiite (PtCu). Skaergaardite developed from a disordered Pd-Cu-rich metal alloy melt that had exsolved from an earlier Cu-(Fe) sulphide melt. Ordering of Pd and Cu (beginning at T ≈ 600°C) results in development of the CsCl structure from a disordered face-centred cubic structure.

Keywords

skaergaarditePd-Cu intermetallicnew mineral speciesCsCl-type structureplatinum-group elementshydroseparationSkaergaard intrusionGreenlandDuluth intrusionMinnesota.
Type
Research Article
Information
Mineralogical Magazine , Volume 68 , Issue 4 , August 2004 , pp. 615 - 632
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2004

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References

Andersen, J.C.Ø, Rasmussen, H., Nielsen, T.F.D. and Rønsbo, J.G. (1998) The Triple Group and the Platinova gold and palladium reefs in the Skaergaard intrusion: stratigraphic and petrographic relations. Economic Geology, 93, 488–509.CrossRefGoogle Scholar
Baker, H., Okamoto, H., Henry, S.D., Davidson, G.M., Fleming, M.A., Kacprzak, L. and Lampman, H.F. (1992) Alloy Phase Diagrams. AmericanSociety for Metals, Metals Park, Ohio, USA.Google Scholar
Bayliss, P., Bernstein, L.R., McDonald, A.M., Roberts, A.C., Sabina, A.P. and Smith, D.K. (2001) Mineral Powder Diffraction File Data Book, Sets 1–50. International Centre for Diffraction Data.Google Scholar
Bird, D.K., Brooks, C.K., Gannicott, R.A. and Turner, P.A. (1991) A gold-bearing horizoninthe Skaergaard Intrusion, East Greenland: Economic Geology, 86, 1083–1092.Google Scholar
Bruno, E., Ginatempo, B. and Giuliano, E.S. (2001) Fermi surface incommensurate nestings and phase equilibria inCu-Pd alloys. Physical Review B, 63, 174107–1–8.CrossRefGoogle Scholar
Cabri, L.J. (2002) The platinum-group minerals. Pp. 13–129 in: The Geology, Geochemistry, Mineralogy and Mineral Beneficiation of the Platinum-Group Elements (Cabri, L.J., editor). Special Volume 54, Canadian Institute of Mining, Metallurgy and Petroleum.Google Scholar
Cabri, L.J. (2004) New developments in process mineralogy of platinum-bearing ores. Proceedings of the Canadian Mineral Processors, 36th annual meeting, pp. 189–198.Google Scholar
Challis, G.A. and Long, J.V.P. (1964) Wairauite – a new cobalt-iron mineral. Mineralogical Magazine, 33, 942–948.CrossRefGoogle Scholar
Ellis, W.C. and Greiner, E.S. (1941) Equilibrium relations in the solid state of the iron-cobalt system. Transactions of the American Society of Metals, 29, 415–434.Google Scholar
Irvine, T.N. (1992) Emplacement of the Skaergaard Intrusion. Carnegie Institution of Washington Year Book, 91, 91–96.Google Scholar
Irvine, T.N., Andersen, J.C.Ø and Brooks, X.X. (2001) Excursionguide to the Skaergaard intrusion, Kangerdlugssuaq area, east Greenland. International Geological Correlation Project, 1.Google Scholar
Jambor, J.L. and Grew, E.S. (1990) New mineral names. American Mineralogist, 75, 240–246.Google Scholar
Karup-Møller, S. and Makovicky, E. (1999) The phase system Cu-Pd-S at 900 degrees, 725 degrees, 550 degrees, and 400 degrees C. Neues Jahrbuch für Mineralogie, Monatshefte, 1999, 551–567.Google Scholar
Kravchenko, T.A. and Kolonin, G.R. (1996) Dependences of stable forms of platinum and palladium on the composition of copper-containing sulphide associates (by experimental data). Experiment in Geosciences, 5, 53–54.Google Scholar
Komppa, U. (1998) Oxide, sulphide and platinum mineralogy of the South Kawishiwi and Partridge River Intrusions of the Duluth Layered Intrusion Complex, Minnesota U.S.A. MSc thesis, Department of Geosciences, University of Oulu, Finland, 104 pp. (in Finnish).Google Scholar
Kwitko, R., Cabral, A.R., Lehmann, B., Laflamme, J.H.G., Cabri, L.J., Criddle, A.J. and Galbiatti, H.F. (2002) Hongshiite, PtCu, from itabirite-hosted Au- Pd-Pt mineralization (Jacutinga), Itabira district, Minas Gerais, Brazil. The Canadian Mineralogist, 40, 711–723.CrossRefGoogle Scholar
Makovicky, E. (2002) Ternary and quaternary phase systems with PGE. Pp. 131–175 in: The Geology, Geochemistry, Mineralogy, Mineral Beneficiation of the Platinum-Group Elements (Cabri, L.J., editor). Special Volume 54, Canadian Institute of Mining, Metallurgy and Petroleum.Google Scholar
Nielsen, T.D.F., Rasmussen, H., Rudashevsky, N.S., Kretser, Yu.L. and Rudashevsky, V.N. (2003) PGE and sulphide phases of the precious metal mineralization of the Skaergaard intrusion. Part 2: sample 90-24 1057. Geological Survey of Denmark and Greenland report 2003/48, 20 pp.Google Scholar
Nolze, G. and Kraus, W. (1998) Powdercell, v. 2.3. Federal Institute for Materials Research and Testing, Berlin, Germany.Google Scholar
Nowotny, H. and Winkels, A. (1939) Zur Überstruktur von b-Messing. Zeitschrift für Physik, 114, 455–458.CrossRefGoogle Scholar
Power, M.R., Pirrie, D., Anderson, J.C.Ø and Butcher, A.R. (2000) Stratigraphical distributionof platinumgroup minerals in the Eastern Layered Series, Rum, Scotland. Mineralium Deposita, 35, 762–775.CrossRefGoogle Scholar
Rudashevsky, N.S., Garuti, G., Andersen, J.C.Ø., Kretser, Y.L., Rudashevsky, V.N. and Zaccarini, F. (2002) Separationof accessory minerals from rocks and ores by hydroseparation (HS) technology: method and application to CHR-2 chromitite, Niquelândia, Brazil. Transactions, Institution of Mining and Metallurgy/ Proceedings Australasian Institute Mining Metallurgy, Section B: Applied Earth Science, 111, 87–94.Google Scholar
Rudashevsky, N.S., Lupal, S.D. and Rudashevsky, V.N. (2001) The hydraulic classifier. Russia patent N 2165300. Patent Cooperation Treaty PCT/ RU01/ 00123 (Moscow: 20 April 2001; 10 May 2001) (in Russian and English).Google Scholar
Saini-Eidukat, B., Weiblen, P.W., Bitsianes, G. and Glascock, M.D. (1990) Contrasts between platinum group element contents and biotite compositions of Duluth Complex troctolitic and anorthositic series rocks. Mineralogy and Petrology, 42, 121–140.CrossRefGoogle Scholar
Stanley, C.J., Criddle, A.J., Förster, H.-J. and Roberts, A.C. (2002) Tischendorfite, Pd8Hg3Se9, a n ew mineral species from Tilkerode, Harz Mountains, Germany. The Canadian Mineralogist, 40, 739–745.CrossRefGoogle Scholar
Wang, K. (1986) Zhanghengite – a new mineral. Acta Mineralogica Sinica, 6, 220–223.Google Scholar
Yu, Z. (2001) New data on daomanite and hongshiite. Acta Geologica Sinica, 75, 458–465.Google Scholar

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