Pure gold is better than pure silver , simple because gold is more acid resistant. And your hands are full of strange acids your cd-r's dislike. I don't mean these Goldish paint cd-r manufacturers put on , but a real golden layer.
For cd manufacturing they usually do not use pure silver or gold of course , simply because it would be extremely expensive. I think you're safe when you have a acid resistant and UV (UltraViolet radiation) resistant cd layer.
In matters of UV the Hi-Space line has a very nice black cd :
They also have an excellent audio cd :
Both can be purchased using the Cd Freaks Webshop. Dunno if its possible to ship outsite The Netherlands yet.