Occurrence of new phosphides and sulfides of Ni, Co, V, and Mo from chromitite of the Othrys ophiolite complex (Central Greece)

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Authors

  • Elena Ifandi
  • Basislios Tsikouras
  • Tassos Grammatikopoulos
  • Daniela Mauro
  • Luca Bindi
  • Chris Stanley

Organisational units

External Organisational units

  • University of Patras
  • Universiti Brunei Darussalam
  • SGS Canada Inc, Ontario
  • Università di Pisa
  • University of Florence
  • Natural History Museum, London

Abstract

Unnamed phosphides of Ni, Co, V, Mo, and one V-sulfide were found in a chromitite of the Agios Stefanos mine (Othrys ophiolite, Central Greece). Most of the phosphides have a stoichiometry similar to allabogdanite or barringerite but show significant proportions of Co, V, and Mo. The minerals could correspond to a Ni-allabogdanite or Ni-barringerite, and to a V-allabogdanite or V-barringerite. More complex stoichiometries are observed when Mo is the dominant metal, and thus it leads to a potentially new (Mo,V,Fe) 3(Ni,Co) 2P mineral. The sulfide corresponds to the ideal formula VS. All the grains vary in size between 5 and 80 μm, and show distinctive reflectance and optical properties. In contrast, Raman spectra are not significantly distinctive. The rare minerals occur intergrown with brecciated chromite, awaruite, and various sulfides produced by alteration of chromitite under reducing conditions. Interpretation of their origin is still speculative embracing a number of possible processes: i) high-temperature reaction of the chromitites with reducing fluids, at mantle depth, ii) low-temperature alteration during serpentinization, iii) post-orogenic, surface lightning strike, or iv) meteorite impact. The minerals described in this work potentially represent new mineral species that are still under study for a complete crystallographic characterization, as required for the acceptance by the IMA Commission on New Minerals, Nomenclature and Classification.

Details

Original languageEnglish
Pages (from-to)105-119
Number of pages15
JournalPeriodico di Mineralogia
Volume88.2019
Issue number3
DOIs
Publication statusPublished - 2 Dec 2019