Ipanema, the most stylish neighborhood in the city, is home to Rio's best jewelers. Local giant H. Stern (113 Rua Garcia d'Avila; 55-21/2274-3447; hstern.com.br) sells plenty of big semiprecious stones in sometimes ho-hum settings. Instead, ask to see the good stuff: The modern design collection includes pieces by major Brazilian designers, like Anna Bella Geiger's gold earrings and bracelets displaying maps of the Amazon ($250–$9,000). Just down the street, at designer Antonio Bernardo's shop (121 Rua Garcia d'Avila; 55-21/2512-7204; antoniobernardo.com.br), we were especially taken with a pair of earrings made of thin strands of yellow gold ($1,200) and a one-of-a-kind opal and diamond ring ($12,000). Maria Oiticica (176 Rua Barão de Jaguaripe; 55-21/2522-2447; mariaoiticica.com.br) uses Amazonian materials—woven palm leaves and dyed jarina seeds—for necklaces, cuff bracelets, and dangly earrings. Some of her pieces are at Harvey Nichols in London, but only here can you see the full collection ($20–$360).