I think it's just a high polished lip.....not CC
IMO, the further refined and high polished you get it, IME....it tends to show oxidation a bit faster than if it was just -90% high polished...
You can mitigate that by putting a sealant onto, BUT, for my OCD eyes, putting a LSP on it does mute the high polish a little bit. Many may not notice the clarity difference.....but for anything high polish, I tend to leave it raw as I don't like the look of a LSP ontop. More maintence as such