Glass is a liquid's atomic disorder frozen into a solid's rigidity, and every trick used to make it flat, strong, or shatter-safe is really a trick for controlling internal stress rather than changing the material itself. The float process floats molten glass on tin to make it flat; tempering and ion exchange both lock a compressed skin around a stressed core to make it strong — and it's the same core idea behind both a car windshield and a phone screen.
Glass
-
Glass: From Sand to Gorilla Glass