So I know, in the abstract, that copper beads can be enameled, but it's not something I had ever tried to do. I had an idea for a necklace that would involve a copper bead or beads, so I ordered some beautiful textured and openwork copper beads to try out. While the results weren't perfect, I think it's a great first step and I'm looking forward to more experimenting.
These are all coated in clear enamel, called flux in the enameling community (I know that's confusing for all the jewelers). I would probably give them another coat in a color for jewelry, but the clear gives me proof of concept. I might even try to plique-a-jour the smaller openwork beads, you can see on the bead in the front that the enamel is already starting to cover the open spaces. Plique-a-jour is another enameling technique I don't have any experience with, enamel is applied to open spaces and fired, creating a stained-glass effect.
I ordered the gigantic copper bead on a lark, it's a bit too big for a necklace but I think it'd make a great ornament.