We present the compositional analysis of three terrestrial analogues of Martian olivine-bearing
rocks derived from both laboratory and flight-derived analytical instruments. In the first step,
state-of-the-art spectroscopic (XRF, NIR and Raman) and diffractometric (XRD) laboratory
systems were complementary used. Besides providing a detailed mineralogical and geochemical
characterization of the samples, results comparison shed light on the advantages ensured by the
combined use of Raman and NIR techniques, being these the spectroscopic instruments that will
soon deploy (2021) on Mars as part of the ExoMars/ESA rover payload. In order to extrapolate
valuable indicators of the mineralogical data that could derive from the ExoMars/Raman Laser
Spectrometer (RLS), laboratory results were then compared with the molecular data gathered
through the RLS ExoMars Simulator. Beside correctly identifying all major phases (feldspar,
pyroxene and olivine), the RLS ExoMars Simulator confirmed the presence of additional minor
compounds (i.e. hematite and apatite) that were not detected by complementary techniques.
Furthermore, concerning the in-depth study of olivine grains, the RLS ExoMars simulator was
able to effectively detect the shifting of the characteristic double peak around 820 and 850 cm 1
, from which the Fe-Mg content of the analysed crystals can be extrapolated. Considering that
olivine is one of the main mineral phases of the ExoMars landing site (Oxia Planum), this study
suggests that the ExoMars/RLS system has the potential to provide detailed information about
the elemental composition of olivine on Mars.
