The early virtreous materials, Egyptian blue, faience, and frit can be readily identified on the basis of the microstructrure as revealed in polished section on the scanning electron microscope (SEM). The differences in microstructure of these materials is discussed. The importance of the correct identification of these vitreous materials to the investigation of the technological developments in their production is stressed. X-ray diffraction analysis is offered as an alternative to SEM when sampling size is limited. The production of Egyptian blue is examined. For related articles, see also <i>AATA</i><b> 23-1355, 21-1943</b>, and <b>20-796</b>. -- AATA