Geophysical and Environmental Research (GER) 63 channel scanner data were used to map the surface mineralogy of Makhtesh Ramon, Negev, Israel. The data werecorrected to reflectance using the Internal Average Relative Reflectance (IARR) method and analysed using colour-composites, the Spectral Angle Mapper (SAM), and linear spectral unmixing (UNM). Results demonstrate that imaging spectrometer data can be used to produce detailed mineralogical maps in arid terrains even when no calibration measurements are made during the flights and no ground measurements are available. The mineralogical maps produced using the GER data compare favourably to the known surface mineralogy, however, they provide greater detail regarding composition and mineral abundance than the existing geological maps.