As stressed by , in her study about the Raman spectroscopy of synthetic and natural iron oxides and (oxy)hydroxides, "most of them can be identified by magnetic methods, but there are some minerals that are not easy to differentiate from each other. In these cases, the magnetic methods can be complemented by Raman spectroscopy" . However, Raman spectroscopy must be carefully used: "A major challenge is the fast transformation of many iron minerals if laser power is applied, especially if the material is poorly crystallized as often is the case in environmental material" . Monika Hanesch used very low laser powers. But, even with low powers, "the investigated iron minerals could be distinguished from each other."