[enzo1]

" rather than use sapphire, Apple turned to potassium to create its “ion-strengthened glass” screen — bathing the glass in the element is what creates the stronger glass.

But to make that glass actually function as a touch screen, three other elements are needed — indium, tin and oxygen. Indium oxide and tin oxide are combined to create indium tin oxide, which then goes into the transparent film in the screen that conducts electricity and makes it responsive"