I think it's probably something else if it's not consistent. And I wouldn't plate it since you paid for RG. Can you return the chain? Or is this a necklace that's one piece?
I think I can return or change the chain as it's not fixed on the pendant. What I think is crazy is that I wore this necklace for a few months without any problems. Today I tried wearing it but my neck is hurting all the time. But again, no rashes or anything - that can't be a real allergy then, right?
However, I was considering buying a butterfly necklace in RG where the chain is affixed to the pendant and now I'm wondering whether it would be better to buy it in platinum, just to be on the safe side.