Fig. 3From: On the formation of hörnesite in a Fatimid manuscript folioBackscattered electron images of samples of the orange-yellow pigment (top, ×2850), and of the white crystals (bottom, ×1500) obtained from the recto of the folio. The letters refer to the locations where the spectra shown in Fig. S1 (Additional file 1) and Fig. 5 were acquiredBack to article page