Annealing of this material is accomplished in lehrs. An industrial method to produce a type of this material lays liquid raw materials over tin to form a float. Diffusion of interfering ions described by the Nikolsky–Eisenman (10[1])equation across this material is seen in electrodes, (10[1])which can be used to measure pH. Sintering particles of this material into hollow disks creates fritted examples of these materials (-5[1])that are used as filters. Addition of boron trioxide lowers (10[1])the coefficient (10[1])of thermal expansion of these materials. Silica, (-5[1])soda ash, and limestone produce the molten form of this material, which is then solidified by blowing. (10[1])For 10 points, (10[1])what (10[1])amorphous material (10[2])is often used to make lab materials and window panes? ■END■ (10[1])