WinPclclas, A WINDOWS PROGRAM FOR PYROCHLORE SUPERGROUP MINERALS

A Microsoft (R) Visual Basic program, WinPclclas, has been developed to calculate the chemical formulae of pyrochlore supergroup minerals (PSM) based on data obtained from wet -chemical and electron -microprobe analyses. These are also classi fi ed following the nomenclature scheme adopted by the Commission on New Minerals, Nomenclature and Classi fi cation (CNMNC) of the International Mineralogical Association for PSM (IMA-10) and including both subsequent group and species updates. The program considers classi fi cation among the 33 IMA-approved PSM, as well as ten species that have not been approved, adhering to the general formula A 2 B 2 X 6 Y and considering the dominant ions at the A , B , and Y sites. It considers PSM represented by the pyrochlore, microlite, rom & eacute;ite, elsmoreite, and beta fi te groups, along with unassigned members of the ralstonite and coulsellite groups. Mineral formulae of the PSM are calculated based on the ideal number of B cations being two apfu , owing to the potential for vacancies at the A , X , and Y sites. WinPclclas operates in four stages: (1) it estimates cation and anion contents provided by input chemical data; (2) it determines the dominant cation and anion at the A , B , and Y sites; (3) it assigns the PSM to one of the seven groups, based on the dominant cation at the B site ( i.e ., W 6+ , Nb 5+ , Ta 5+ , Sb 5+ , Ti 4+ , Al 3+ , and Mg 2+ ); and (4) it classi fi es the pyrochlore species into an appropriate group, based on the dominant cation at the A site and the dominant anion at the Y site. The H 2 O (wt. % ) content for the PSM is estimated by stoichiometric constraints. WinPclclas allows users to: (1) enter up to 51 input variables for mineral -chemical analyses; (2) type and load multiple PSM compositions in the data entry section; (3) edit and load the Microsoft (R) Excel fi les used in calculating, classifying, and naming the PSM, together with the total monovalent to hexavalent cation, and (4) store all the calculated parameters in the output of a Microsoft (R) Excel fi le for further data evaluations. The program is distributed as a self -extracting setup fi le, including the necessary support fi les used by the program, a help fi le, and representative sample data fi les.