Here, independent of the position in the gastrolith, all mineral shows a very similar, amorphous diffraction pattern consisting of two broad Gaussian-shaped bands (AMO1 and AMO2) with maxima at around 22 nm1 and 31 nm1. However, after careful fitting the bands with Gaussians we can observe that the position of the fitted peak at 22 nm1 shifts to lower values at the same places in the gastrolith where EDS shows a higher P-concentration (Fig. 7B, left axis and Fig. 7C, right axis).