> Adding a thin coating of gold would not necessarily change that structure My confusion is that I would normally expect a layer of gold not to permit any ligh

> Adding a thin coating of gold would not necessarily change that structure My confusion is that I would normally expect a layer of gold not to permit any light to pass through. The underlying structure wouldn't be receiving any light, so there would be no photons to trap. Apparently a layer of gold can be applied thinly enough to transmit appreciable light, though.