If it is pre 1.8 (I believe that was the patch) stuff, you can't enchant it. If you're on console, I believe that means anything dropped before the release of RoS. As for what it takes, it is just that level appropriate crafting materials + gold. If it is a legendary, it might take gems (not sure if that is only for max level things).
I'm on X360. Both the amulet and ring are level 60 (Compass rose & set matching amulet) that I carried over from before RoS. Trying to figure out if it's a no go since they are pre RoS or just because I don't currently have the required materials. What are the required materials to enchant rings / amulets?