There is an apparent mismatch between electron paramagnetic resonance and Mössbauer spectroscopy results on the charge and spin states of dilute Fe impurities in NaCl; Mössbauer spectroscopy data have been interpreted in terms of high-spin Fe 2+, while electron paramagnetic resonance studies suggest low-spin Fe 1+. In the present study, the charge and spin states of dilute substitutional Fe impurities in NaCl and LiF have been investigated with Mn 57→ Fe 57 emission Mössbauer spectroscopy. A scheme is proposed which takes into account the effects of nearest-neighbor distances and electronegativity difference of the host atoms on the Mössbauer isomer shift and allows for the unequivocal differentiation between high-spin Fe 2+ and high/low-spin Fe 1+ in Mössbauer spectroscopy. From these considerations, the Mössbauer results are found to be consistent with dilute Fe impurities in NaCl and LiF in …