Here we present an adapted version of the Modified Gaussian Model (MGM), a tool developed to detect and characterize both simple and complex mineralogies in magmatic rocks, and we review the results we obtained over the last years on four different planetary bodies. We first describe the working principle of the adapted MGM technique, with the differences compared to the original version, and the validation process using various laboratory and natural spectra. We then describe the results obtained on the Oman ophiolite (Earth), taken as a planetary spectral analog for magmatic terrains. We finally present spectroscopy-based mineralogical maps and some petrologic implications for key regions of Mars, the Moon and asteroid (4) Vesta.