Glass is one of the engineer's most useful and versatile materials. Its properties can be engineered widely in order to provide a range of physical, mechanical, electrical, and optical uses for practically every type of environmental condition. The transparency of glass facilitates inspection of process operations and minimizes the risk of failure due to unsuspected corrosion, while its hardness and smoothness contribute to easy cleaning. The development of glass-ceramic composites has further extended the range of glassy engineering materials. Glass-ceramics combine the formability of glasses with many of the advantageous properties of ceramics and find application by virtue of their strength and high chemical durability particularly at elevated temperatures. This chapter comprises two contributions from the 3rd edition of Shreir: Glass and Glass Ceramics by Oliver and Proctor; and Vitreous Silica by May, which have been combined by the editors, with minor updating, for this current edition.
