Do impurities increase the band gap in glass so that it becomes transparent from being opaque as sand? If yes, what are these impurities?

Question

Do impurities increase the band gap in glass so that it becomes transparent from being opaque as sand? If yes, what are these impurities?

In: Physics

Answer 1

Sand is opaque due to its roughness. If you grind rough the surface of transparent glass it will also be opaque. Sand has this roughness all the way through. Sand does, however, have impurities that can discolor it, which is why it usually isn’t white like sugar.