Fig. 8

a Colour image derived from PRISMS images of ‘Area 35’ on the Selden map (Fig. 1) with a white circle marking the position where the reflectance spectrum was extracted; b KM model fit (blue circles) using a combination of atacamite, indigo and orpiment to the measured PRISMS reflectance spectrum (black crosses) for a green area; the spectrum of a green fragment measured with a spectrometer (red curve) is also plotted to show the spectral similarity between the fragment and the green region on the map; c EDX spectra from a green fragment showing the presence of copper, chlorine and arsenic; the left inset shows the SEM copper map and the right inset shows the SEM chlorine map; d Micro-Raman spectra from two green fragments showing spectral features corresponding to orpiment and indigo