A quantitative analysis of iron-silicide precipitate stability with respect to time and temperature is presented. Iron precipitation and dissolution in silicon was analyzed by a quantitative assessment of change in interstitial iron using a surface photovoltage minority carrier lifetime/diffusion length analysis technique. Interstitial iron is shown to rapidly precipitate to the silicide phase between 500 and 600 degrees C. Iron-silicide precipitates were found to dissolve above a temperature of 760 degrees C. Dissolution of FeSi2 precipitates releases iron back to an interstitial position in the silicon matrix. The amount of precipitate dissolved was found to be a function of dissolution process temperature and time. It is concluded that the precipitate phase of iron, FeSi2, is thermally unstable above a temperature of 760 degrees C.