Funny enough I watched antiques roadshow this week and there was a VERY fancy ring. Yes 1920s. Yes platinum. And yes in 2008 when this roadshow aired it was about 10k. If she had the original bill of sale it would be 50k. But the value today (15 yrs later) definitely went down. So the last time it was appraised it might have been appraised at insurance value and not say auction. And it might have depreciated. And. Someone might have gotten it in their head to remove any gemstones and not say anything. So get it appraised first. Then make some plans. And they likely won't be the type of plans you think.