THE technique and application of 57Fe Mossbauer spectroscopy to minerals have been discussed fully1–3 in the context of the determination of oxidation states, coordination numbers, and site symmetry and population. This report shows, with the particular example of metamict thoro-steenstrupine {Na2Ce(Mn,Fe,Ta)(La,Th,…)[(Si,P)O4]3H2}, that the Mossbauer technique can yield structural information even when X-ray diffractometry is not possible because of the destruction of the lattice ordering by the damage produced by radioactive decays.