CHROMITE: A program to process electron microprobe data from Cr-rich spinels

Spinels are important petrogenetic or geotectonic minerals and are widespread in many ultramafic, mafic igneous and metamorphic rocks. Chromian spinel chemistry plays an important role in classifying mantle-derived peridotites and estimating equilibrium temperatures in olivine-bearing rocks. It is also used as a speedometer that shows the cooling rate of rocks and as an oxygen barometer for upper mantle rocks. The aim of this work is to develop a computer program to calculate and plot the chemical analyses of Cr-rich spinels. Hence, a program termed CHROMITE was written for IBM-PC users interested in the microprobe analysis of Cr-rich spinels. The program runs under DOS and Windows systems with minimum hardware requirements. It is easy to use and understand the software with pull-down menus and base function keys. By entering electron microprobe spinel analyses, CHROMITE program provides the earth scientists with a convenient means to calculate cation numbers from major oxides or elements and to determine important parameters together with the end members based on 4 or 32 oxygen base. This program is well suited to a variety of binary and ternary diagrams that were currently used for spinel chemistry. All calculations can be stored in comma-delimited (ASCII) file format for further spreadsheet processing. The compiled form of CHROMITE takes up approximately 600 kilobytes and it is available from the author on request.