The Raman spectra of a suite of geological mineral specimens which are relevant to Martian planetary exploration are reported under different conditions of spectral resolution at a fixed laser excitation wavelength of 1064nm. As found with an earlier study of biomolecular systems, the observed Raman spectra are significantly altered under different conditions of spectral resolution; in particular, the discrimination between several minerals no longer becomes possible as the spectral resolution decreases beyond 16cm−1. These results have important implications for the construction and evaluation of miniaturised Raman spectrometers for space flight missions and incorporation into instrumentation for landers and rovers being proposed for missions to Mars in the next decade.