Iron and chromium absorption bands in the spectra of terrestrial pyroxenes - Application to mineralogical remote sensing of asteroid surfaces

The dependence of the position of Fe(2+) and Cr(3+) absorption bands in the spectra of terrestrial pyroxenes on temperature is investigated. A SW shift (about 10 nm) of the 0.95-micron Fe(2+) band and the absence of a Cr(3+)-band shift in the interval from room temperature to nitrogen temperature are found. The possibility of remote diagnostics of the composition of pyroxenes from the position of the Fe(2+) absorption band in the center at 0.505 micron is shown.