Many 47th Street jewelers will offer to buy gold or diamond jewelry.
You need to be just as diligent in shopping around for a buyer as you would when making a purchase.
This is a lot easier in the Diamond District because there are so many merchants offering to buy precious jewelry.
In selling your jewelry, make sure the dealer has a properly displayed second hand dealers license from the New York City Department of Consumer Affairs.
While you may only care about the most cash you can get for your gems, the licensing law protects other consumers by preventing the resale of stolen merchandise.