If the ring is new but only the stone is "used", it´ll be hard to be discovered and still much cheaper. Even a refinished old ring would be quite hard to tell a

If the ring is new but only the stone is "used", it´ll be hard to be discovered and still much cheaper. Even a refinished old ring would be quite hard to tell apart from a brand new one (unless your fiance is quite an expert on ring designs, and able to tell apart if a ring is 20 years old, then of course you better buy a new one). But don´t do it if you are not good at keeping secrets...