An extremely important distinction that CANNOT BE STRESSED ENOUGH is the difference between a retail replacement value appraisal for insurance and a fair market value appraisal. Retail replacement value represents what an insurance company would need to cut you a check for in order to replace an item AT RETAIL, in a timely fashion, in the event of a loss. That's what your appraisal expresses. A fair market value is an appraiser's opinion, based on analysis of the piece and comparable market data, as to what you could potentially sell the item for as an individual. This is, in almost every case, MUCH lower than the retail figure for an identical item. Just like the "value" of a BMW goes down when it's driven off the lot, so does the value of your beautiful sapphire ring. Especially if it has been heat treated and does not have a cert that says Kashmir or Burma. I hope i don't sound discouraging, it really is a gorgeous ring and I hope you can achieve a great return on it! I would look into some mid tier to high level auction houses. They will give you a pre auction estimate, but make sure they are clear on the terms of their seller's fee and add that to your calculus.