They buy scrap gold, but rarely buy diamonds or other jewels. They will give you a general appraisal, so you can decide whether selling a piece as a whole somewhere else might be a better choice, but don't appraise things like the quality of the stones. You get paid on the gold weight. They remove a certain number of stones for free (6, if I remember correctly), then they charge you (I think it's $10/stone). The other reply is correct, you get a higher pay out of you take store credit.
If i remember right you can but you get more 'bang fpr your buck' on in store credit compared to walking out with cash.
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