Glass

[1] A transparent, hard, amorphous, brittle substance which is made by fusing together one or more of the oxides of silicon, boron, or phosphorus, with certain basic oxides (e.g., sodium, magnesium, calcium, potassium), and cooling the product rapidly to prevent crystallization or devitrification. The melting point varies between 800°C and 950°C but it is worked at higher temperatures. The tensile strength of glass resides almost entirely in the outer skin; if this is scratched or corroded, the glass is much more easily broken.
[2] The transparent windows in a vehicle.
See also body glass, compound glass, door glass, laminated glass, laminated windshield glass, milled glass fiber, safety glass, sight glass, tempered glass, tinted glass, toughened glass