Determination of the spinel group end-members based on electron microprobe analyses


The spinel group minerals have been the focus of many studies, not only because of their economic interest, but also due to the fact that they are very useful as petrogenetic indicators. The application End-Members Generator (EMG) allows to establish, based on electron microprobe analyses (EMPA), the 19 end-members of the spinel group: MgAl2O4 (Spinel sensu stricto, s.s.), FeAl2O4 (Hercynite), MnAl2O4 (Galaxite), ZnAl2O4 (Gahnite), MgFe2O4 (Magnesioferrite), Fe3O4 (Magnetite), MnFe2O4 (Jacobsite), ZnFe2O4 (Franklinite), NiFe2O4 (Trevorite), MgCr2O4 (Magnesiochromite), FeCr2O4 (Chromite), MnCr2O4 (Manganochromite), ZnCr2O4 (Zincochromite), NiCr2O4 (Nichromite), MgV2O4 (Magnesiocoulsonite), FeV2O4 (Coulsonite), MnV2O4 (Vuorelainenite), Mg2TiO4 (Qandilite) and Fe2TiO4 (Ulvöspinel). EMG is an application that does not require an installation process and was created with the purpose of performing calculations to obtain: cation proportions (per formula unit, p.f.u.), end-members of the spinel group, redistribution proportions for the corresponding end-members in the Magnetite prism or Ulvöspinel prism and a data validation section to check the results. EMG accepts .csv data files and the results obtained can be used to represent a given dataset with the SpinelViz program or any other 2D and/or 3D graph plotting software.

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This work was financed with projects 24/H108 and 24/N028 - General Secretariat of Science and Technology of the Universidad Nacional del Sur granted to E.A. Bjerg and S. M. Castro, and PIP 112-201101-00285 - National Scientific and Technical Research Council of Argentina granted to E.A. Bjerg. G.R. Ferracutti is grateful to Ing. Susana Kahnert for helpful comments and suggestions. A previous version of this manuscript benefited from the constructive corrections and suggestions made by Dr. Cees-Jan De Hoog and Dr. Marek Locmelis.

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Correspondence to Gabriela R. Ferracutti.

Additional information

Editorial handling: F. Gervilla

Electronic supplementary material

Below is the link to the electronic supplementary material.

Electronic Supplementary Data 1

Example of .csv input data entry (XLSX 14 kb)

Electronic Supplementary Data 2

Example of output .csv cations proportions (XLSX 13 kb)

Electronic Supplementary Data 3

Example of output .csv data validation (XLSX 18 kb)

Electronic Supplementary Data 4

Example of output .csv with discrimination Fe2O3 from FeO (XLSX 13 kb)

Electronic Supplementary Data 5

Example of output .csv with 19 end-members (XLSX 15 kb)

Electronic Supplementary Data 6

Example of output .csv with redistribution proportions for the corresponding prisms end-members. (XLSX 12 kb)

Electronic Supplementary Data 7

(ZIP 17.4 mb)

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Ferracutti, G.R., Gargiulo, M.F., Ganuza, M.L. et al. Determination of the spinel group end-members based on electron microprobe analyses. Miner Petrol 109, 153–160 (2015).

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  • ZnFe2O4
  • ZnAl2O4
  • MnFe2O4
  • NiCr2O4
  • FeAl2O4