a dealkalized surface may have either no alkali remaining or may just have less than the bulk. in silicate glasses, dealkalized surfaces are also often considered "silica-rich" since the selective removal of alkali ions can be thought to leave behind a surface composed primarily of silica (sio). to be precise, dealkalization does not generally involve the outright removal of alkali from the glass, but rather its replacement with protons (h) or hydronium ions (ho) in the structure through the process of ion-exchange.