We have already seen a few of the principle processes that are involved in forming glass products. Of equal significance, however, is the fabrication of crystalline ceramic products. In most cases these processes require a combination of a forming stage where the shape of the article is made and then a subsequent firing stage to obtain a rigid structure with the desired properties.
Crystalline ceramics can be divided into traditional ceramics, based primarily on clays with additional quantities of quartz and feldspars, and on engineering ceramics, which are mainly compounds made up of oxides, carbides, or nitrides.