Radioactive 57Mn+ ions have been implanted into a natural diamond held at 300–1100 K for Mössbauer spectroscopy studies on the 14 keV γ-radiation emitted in the decay of the 57Fe daughter atoms. The Mn parent isotopes are found to be implanted into defect sites of non-cubic symmetry, which anneal partially with increasing temperature during the 57Mn lifetime. This is concluded to lead to their incorporation on substitutional lattice sites. This site is inherited by the majority of the 57Fe daughter atoms, however, a sizeable fraction is expelled into interstitial sites owing to the recoil in the nuclear $\beta^-$-decay. Thus the Fe isomer shifts in both lattice sites have been determined.