You're better off with an estate jeweler who deals with those kinds of items. If, however, you want to hock your Swatch watch, visit a pawnbroker who trades in more modest merchandise. Have reasonable expectations. Sentimental value doesn't count here. Jewelry is just a commodity, and price is determined by the market value.
Some items hold their value better than others.
Co. But you may get less than half the original purchase price for a diamond because there is such a markup at the retail level. Some people expect to get more than they paid originally. That won't happen unless it's a true antique. If you still have the original receipt, box, warranty, accessories or anything else that goes with a piece, bring it along. It helps prove the item's authenticity.