If you buy 2 CVO's, you'll have a perfectly good set of earrings. I actually tried the necklace thing when I opened the box with the key. I put it on the chain for a moment, held it up and looked at it for a few seconds, and decided against it. I'm giving you a vote of "no" on using it on a necklace, but to each his own. If they change the little eyelit hole at the top of the key to go the other direction, so it doesn't sit at an angle on the chain, it may be a little better, but then again as it was mentioned, you will likely find your skin discolored after wearing it for a short time. So again, I vote "no".
I still think that if you buy 2 CVO's and give both keys to your wife as earrings, I'm sure you'll have no trouble explaining to her that she is the only person on the block with $60,000 earrings. Yeah, that's the ticket!