Close to 150 specimens of Egyptian faience from three museums were subjected to several types of analysis in order to differentiate ordinary faience from variants according to the Lucas classification scheme. X-ray fluorescence and atomic absorption spectra data provided the compositional analysis of the materials. Concludes two oases seem to be the most likely source of New Kingdom cobalt. Generally the chronological changes in the composition of frits parallel the changes in faience and glass. Classification should be based upon the color of the body.