Figure 2
Multi-modal imaging obtained during a single experiment, simultaneously using absorption, fluorescence and DSCT probes on a sample containing chalcedony (SiO2, P3121, a = 4.9134, c = 5.4052 Å) and iron pigments inside a capillary. Absorption images show contrast between areas having different attenuation coefficients, mainly given by Si (Z = 14) and Fe (Z = 26). Fluorescence is sensitive to the general distribution of elemental Fe, whereas DSCT can discriminate between different structural phases with shared elemental Fe, such as haematite (Fe2O3, [R\overline 3c], a = 5.0355, c = 13.747 Å), siderite (FeCO3, [R\overline 3c], a = 4.6916, c = 15.379 Å) and greenalite [Fe3Si2O5(OH)4, monoclinic C2/m, a = 5.390, b = 9.336, c = 14.166 Å, [beta] = 90.01°] (adapted from Bleuet et al., 2008BB8).  [article HTML]

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