The black coating of Campanian pottery was analyzed by energy dispersive x-ray analysis and by electron microanalysis. The sherd body was investigated by x-ray fluorescence. The phases in the coating and the body were identified by powder x-ray diffraction analysis. The coating is rich in FeO and is very different from the sherd matrix, which is rich in CaO. The mineralogy of both is described, and an estimation of maximum firing temperatures and the reducing conditions is presented.