A stroll through San Telmo, oldest neighborhood in Buenos Aires, is a welcome respite from the Argentine capital’s hectic inner-city streets. With colonial architecture and cobbled streets lined with shops, cafés and tango parlors, San Telmo is the primary destination for antique hunters. Anyone on the prowl for vintage and period jewelry will find treasure tucked in just about every corner of this laid-back barrio.

At the moment, San Telmo's antique shops appear untouched by the current economic struggles in Buenos Aires, but owners say business is down. For antique jewelry lovers looking for bargains, now is a great time to negotiate deals. Inventory is there but demand has dropped and the exchange rate for Americans is good and getting better – particularly if you bring cash and take advantage of the unofficial “blue market” rate (currently 15 pesos to the dollar).

Whether you want to buy or to sell jewelry or watches, the first step in figuring out value is to identify what it is, when and where it was made, and by whom. A maker's mark can help but if jewelry has hallmarks, this process is almost foolproof.

Serpents and wildlife motifs dominated the high-end period jewels on display at the Antique Jewelry and Watch Show in July, as more than 100 watch and jewelry dealers gathered in Manhattan’s Metropolitan Pavilion. Now in its seventh year and growing in prestige, the four-day event was open to the public and attracted around 3,000 private collectors and industry insiders.

The show opened two days before the massive trade-only JA New York summer show, which focuses on high-end contemporary jewelry.