We have studied samples of cobalt‐hardened gold electrodeposits via Mössbauer spectroscopy to search for microprecipitates of gold compounds in situ. Plated layers were found to contain no detectable , , or . The upper limits determined for the presence of these phases exclude the possibility that all the carbon found in this hard gold plate could be incorporated in the deposit in these forms. We have determined the recoil‐free fraction for and .