Customs Rules and Duty Fees of a ring

Well, Jim. It depends on what the ring made from? Does the ring made from gold or silver or any other materials?
If it is made of gold or silver and if the gold is not over 50g, you are allowed to take it in without declaration. If it is over 50g, you are still allowed to take it in, but you have to declare and pay the duty for them.
I think the best way is to take your to China and buy the ring in China to your fiance.
Hope these information can help you.