WinGrt, a Windows program for garnet supergroup minerals

Abstract

A Microsoft® Visual Basic software, called WinGrt, has been developed to calculate and classify wet-chemical and electron-microprobe garnet supergroup mineral analyses. The program evaluates 33 approved species that belong to the tetragonal henritermierite and isometric bitikleite, schorlomite, garnet and berzeliite groups based on the Commission on New Minerals and Mineral Names (CNMMN) of the International Mineralogical Association (IMA–13) nomenclature scheme. WinGrt also evaluates thirty geothermometers using the Fe2+–Mg exchange reactions for garnet–biotite, garnet–clinopyroxene and garnet–orthopyroxene pairs within the application range of greenschist-, amphibolite-, granuliteand eclogite-facies metamorphic rocks. As naturally occurring garnet is potentially a useful provenance indicator, the program calculates end-member molecules from chemical compositions on the basis of different approaches and yields pyrope, almandine, spessartine, grossular, andradite and schorlomite phase on various ternary discrimination diagrams used in provenance studies. The ferric and ferrous iron contents from total FeO (wt. %) amount are estimated by stoichiometric constraints. The program allows the users to enter 30 input variables including Sample No, SiO2, TiO2, ZrO2, HfO2, Th2O, SnO2, Al2O3, Cr2O3, V2O3, Fe2O3, Mn2O3, Sc2O3, Y2O3 + REE2O3, FeO, MgO, MnO, ZnO, CaO, Na2O, Li2O, P2O5, V2O5, Sb2O5, As2O5, Nb2O5, UO3, Te2O3, F and H2O (wt. %). WinGrt also enables the user to enter the total REE2O3 (wt. %) as input values from La2O3 to Lu2O3 (wt. %) of garnet supergroup mineral analyses in program’s data edit section. WinGrt enables the user to type or load multiple garnet compositions in the data entry section, to edit and load Microsoft® Excel files in calculating, classifying and naming the garnet species, and to store all the calculated parameters in the Microsoft® Excel file for further evaluation.