FeO is ferrimagnetic with a Curie temperature of . There is a phase transition at , called Verwey transition where there is a discontinuity in the structure, conductivity and magnetic properties. This effect has been extensively investigated and whilst various explanations have been proposed, it does not appear to be fully understood.
While it has much higher electrical resistivity than iron metal (96.1 nΩ m), FeO's electrical resistivity (0.3 mΩ m ) is significantly lower than that of FeO (approx kΩ m). This is ascribed to electron exchange between the Fe and Fe centres in FeO.