Fig. 2From: An analytical study of the Huexotzinco Codex using X-ray fluorescence, fiber optic reflectance spectroscopy, and portable Fourier-transform infrared spectroscopyMicroscopic images, XRF, and FORS of amate and maguey papers. Microscope images were taken under a halogen and mercury lamp with a ×20 objective. Gypsum related peaks are marked in the XRF (S, K, and Ca) and FORS 1st derivative spectra (1453, 1955, and 1993 nm)Back to article page