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Mineralogy and Petrology

, Volume 113, Issue 4, pp 527–532 | Cite as

Orthocuproplatinum, Pt3Cu, a new mineral from the Lubero region, North Kivu, Democratic Republic of the Congo

  • Alexandre R. CabralEmail author
  • Roman Skála
  • Anna Vymazalová
  • Jaroslav Maixner
  • Chris J. Stanley
  • Bernd Lehmann
  • Jacques Jedwab
Original Paper
  • 37 Downloads

Abstract

Orthocuproplatinum, Pt3Cu, is a new mineral from the Lubero region of North Kivu, Democratic Republic of the Congo. The mineral, which has a synthetic analogue, occurs as a 1.5-mm-long alluvial grain in a heavy-mineral concentrate, together with the holotype specimen of kitagohaite, Pt7Cu. The grain of orthocuproplatinum has a rim of hongshiite, PtCu, and abundant inclusions of calcite. Opaque and metallic, orthocuproplatinum has a whitish colour in reflected light and slightly perceptible anisotropy. The crystal structure of orthocuproplatinum is orthorhombic, space group Cmmm. Its unit-cell parameters: a = 7.681(1) Å; b = 5.4318(8) Å; c = 2.7502(4) Å; V = 114.74(3) Å3; Z = 2. The calculated density is 17.866 g cm−3. The strongest diffraction lines are [d in Å(I)]: 2.337 (11), 2.236 (100), 2.217 (97), 1.932 (61), 1.920 (30), 1.362 (36), 1.169 (24), 1.161 (23). The Vickers hardness is 243 kg mm−2 (VHN25), corresponding to a Mohs hardness of 4. The empirical formula of orthocuproplatinum, calculated from a mean value of 12 electron-probe microanalyses that gave 12.9 wt% Cu and 87.3 wt% Pt, is Pt2.76Cu1.24 on the basis of 4 atoms.

Keywords

Orthocuproplatinum Lubero North Kivu Democratic Republic of the Congo 

Notes

Acknowledgements

The Central Laboratories of the University of Chemistry and Technology, Prague, are thanked for providing access to their microdiffractometer. The authors are indebted to Ulf Hålenius and Ritsuro Miyawaki, the former and present Chairman of the Commission on New Minerals, Nomenclature and Classification (CNMNC) of the International Mineralogical Association, respectively, and the CNMNC members, for their thoughtful comments on the data submitted to the commission. Constructive reviews by Louis Cabri and John Bowles, as well as editorial comments by associate editor Luca Bindi, are sincerely appreciated. This work was supported by the Grant Agency of the Czech Republic (project No. 18-15390S to AV). The institutional support RVO 67985831 of the Institute of Geology of the Czech Academy of Sciences is gratefully acknowledged.

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Copyright information

© Springer-Verlag GmbH Austria, part of Springer Nature 2019

Authors and Affiliations

  • Alexandre R. Cabral
    • 1
    • 2
    Email author
  • Roman Skála
    • 3
  • Anna Vymazalová
    • 4
  • Jaroslav Maixner
    • 5
  • Chris J. Stanley
    • 6
  • Bernd Lehmann
    • 7
  • Jacques Jedwab
    • 8
  1. 1.Centro de Pesquisas Professor Manoel Teixeira da Costa (CPMTC), Instituto de GeociênciasUniversidade Federal de Minas Gerais (UFMG)Belo HorizonteBrazil
  2. 2.Centro de Desenvolvimento da Tecnologia Nuclear (CDTN)Belo HorizonteBrazil
  3. 3.Institute of Geology of the Czech Academy of SciencesPraha 6Czech Republic
  4. 4.Czech Geological SurveyPraha 5Czech Republic
  5. 5.Central LaboratoriesUniversity of Chemistry and TechnologyPraha 6Czech Republic
  6. 6.Department of Earth SciencesNatural History MuseumLondonUK
  7. 7.Technische Universität ClausthalClausthal-ZellerfeldGermany
  8. 8.Université Libre de BruxellesBrusselsBelgium

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