Energetic Heavy Ion Radiation Effect in Brazilian Emeralds

Emerald samples, originating from Goias, Brazil, containing a significant portion of Fe3+ beside Fe2+ were irradiated with 209 MeV 89Kr ions in order to study the effect of irradiation on the valence state of iron. Using 57Fe transmission Mossbauer spectroscopy a valence state transition from Fe3+ to Fe2+ was clearly observed as a result of irradiation.