As with the fashion stores, the big names in jewellery are concentrated in the area around Via Condotti and Via del Babuino near the Spanish Steps. These include Rome-based Bulgari, Pomellato, Buccellati, and Damiani, as well as Cartier and Tiffany.
If you're looking for something a little more unique and hand crafted, don't miss the workshop of goldsmith Massimo Maria Melis, whose work revisits the style of ancient Roman gold working. Loepp & Nagai offer similar designs (perhaps with a more modern twist) on Via dei Barbieri.
Moving away from the retro designs, the area around Via della Stelletta (near the Pantheon) has several artisanal jewellers, including Mateire on Via del Gesu, and the Studio Gioielleria Quattrocolo on Via della Scrofa.
Also on Via della Stelletta, family run business Sirni still makes bags entirely in their workshop behind the store.
For costume jewellery, there is Fabio Piccione on Via del Boschetto, and many of the boutiques on Via dei Banchi Vecchi may be worth checking out as well.