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

Spinels are important petrogenetic or geotectonic minerals and are widespre ad in many ultramafic, mafic igneous ana metamorphic rocks. Chromian spinel chemistry plays an important role in classifying mantle-derived peridotite s and estimating equilibrium temperatures in olivine-bearing rocks. It is a lso used as a speedometer that shows the cooling rate of rocks and as an ox ygen 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 sp inels. Hence, a program termed CHROMITE was written for IBM-PC users intere sted in the microprobe analysis of Cr-rich spinels. The program runs under DOS and Windows systems with minimum hardware requirements. It is easy to u se 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 f rom 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 su ited to a variety of binary and ternary diagrams that were currently used f or spinel chemistry. All calculations can be stored in comma-delimited (ASC II) file format for further spreadsheet processing. The compiled form of CH ROMITE takes up approximately 600 kilobytes and it is available from the au thor on request.