You have a wide variety of options. Where you live could make a difference what choice you make. Auction house – auctions, like the stock market, are highly speculative. You might do quite well, but maybe not. A solid, successful auctioneer knows their regulars pretty well, and can give an idea of y ok it chances, but none worthy of their profession will make a verbal guarantee. Pawn shop – if you want more than twenty percent of its value, stay away from pawn shops. Jewelers – some will sell on consignment, but that is rare. All I know about selling to a jeweler is, some are honest, some are not. For instance, they might try to point out a non existent inclusion, trusting that you don’t understand and will accept their word. You could try selling it yourself. Most areas these days have at least one source on facebook for buy, sell, and trade. There are also eBay, and Amazon. For either of those there would be a few. The big problem to watch out for when selling it yourself, is thieves looking to take it from you. They will pretend interest, and when you show it to them you could be robbed. Whatever method you choose, up your price a bit, so when a buyer succeeds in talking you down, it won’t be too bad.