Fig. 6

XRF compositional maps of both sides of the 1899 dinero coin. a reverse, b obverse. Each side contains elemental maps of the 4 main elements detected, and includes the grid of the measurement points. The compositional maps are self-consistent: the color intensity for each element is proportional to its concentration in the different locations of the coin’s surface. The intensity between elements, however, cannot be considered proportional to their relative concentration. An example of two XRF spectra, one taken on the blackened border, and the other in the center of the reverse side, are shown in c