Very attractive!
I took a leap and bought my wife an identical key; it came with a chain. Amazingly, despite being very vanilla and private, She is so far indicating the intention to wear it. Alas, the chain is too short. So we trundled down to the jeweler and buy a 24-inch chain. Given the amount of money that gold chain will cost, I suspect She intends to wear the thing.
I am trying my hardest to not ruin things by gushing about how awesome it would be for Her to "proudly wear the key". Boys and their excitement.