57 Fe emission Mössbauer spectroscopy has been applied to study the lattice location and properties of Fe in gadolinium gallium garnet Gd 3 Ga 5 O 12 (GGG) single crystals in the temperature interval 300 -563 K within the extremely dilute (<10 −4 at.%) regime following the implantation of 57 Mn (T1 / 2 = 1.5 min.) at ISOLDE/CERN. These results are compared with earlier Mössbauer spectroscopy study of Fe-doped gadolinium gallium (GGG), with implantation fluences between 8×10 15 and 6×10 16 atoms cm −2 . Three Fe components are observed in the emission Mössbauer spectra: (i) high spin Fe 2+ located at damage sites due to the implantation process, (ii) high spin Fe 3+ at substitutional tetrahedral Ga sites, and (iii) interstitial Fe, probably due to the recoil imparted on the daughter 57 * Fe nucleus in the β − decay of 57 Mn. In contrast to high fluence 57 Fe implantation studies the Fe 3+ ions are found to prefer the tetrahedral Ga site over the octahedral Ga site. No annealing stages are evident in the temperature range investigated. Despite the very low concentration, high-spin Fe 3+ shows fast spin relaxation, presumably due to an indirect interaction between nearby gadolinium atoms.