The composition, properties, and industrial production of glass are covered in industrial glass. The physical and atomic characteristics of glass are treated in amorphous solid.
The varieties of glass differ widely in chemical composition and in physical qualities. Most varieties, however, have certain qualities in common. They pass through a viscous stage in cooling from a state of fluidity; they develop effects of colour when the glass mixtures are fused with certain metallic oxides; they are, when cold, poor conductors both of electricity and of heat; most types are easily fractured by a blow or shock and show a conchoidal fracture; and they are but slightly affected by ordinary solvents but are readily attacked by hydrofluoric acid.