Glass Glass is a substance whose form is dependent upon a great number of properties. It can be categorized under different types. Soda-lime glass is theleast expensive of the types for good reason. Lead glass is used most commonly as an art glass. Borosilicate glass has many advantageous properties. Aluminum silicate glass is not quite so common. Ninety-six percent silica glass is the result of the removal of almost all of the non-silicate components in silica glass. Fused silica glass is the most expensive glass and the hardest to fabricate. Glass is an amorphous substance that