Top and middle: mid-infrared part of some of the spectra of (a) olivine (OL) and (b) pyroxene (OPX) irradiated by ions and by laser. The two dotted lines show the approximate positions of the reflectance values (R), based on which the ratio of the peaks was evaluated. The spectra were normalized at the wavelength (λ) of the first peak used for the ratio calculation to highlight the spectral alteration. Bottom: evolution of the reflectance ratio due to different irradiation set-ups. Time, t, was evaluated for the situation at 1 au (see Appendix C). A grey horizontal line indicates the situation of the flattenedpeaks. H⁺ stands for hydrogen, He⁺ for helium, and Ar⁺ for argon ions.