Tin(IV) oxide, also known as stannic oxide, is the inorganic compound with the formula SnO₂. It is a colourless, diamagnetic, amphoteric solid. Tin(IV) oxide has long been used as an opacifier and as a white colorant in ceramic glazes. Tin(IV) oxide can be used as a polishing powder, sometimes in mixtures also with lead oxide, for polishing glass, jewelry, marble and silver.