Sapphire and diamond ring, 1920s. This simple and elegant design is actually fiendishly difficult to produce, requiring perfectly sized sapphires and mastery of different setting techniques. The calibré-cut sapphires would have been shaped especially for this setting, where they are threaded onto a metal channel and held in place with horizontal bars. This ensures that no settings are visible from the front, and the central motif is a pure, deep blue line of seamless sapphires, beautifully matched for colour. The single-cut diamonds are pavé-set, where individual apertures are cut into the band, the stones are each held in place by minute claws at each corner. Such challenging techniques would have taken years to master, with contemporary jewellers struggling to emulate this level of handiwork. This sleek design fits alongside solitaire rings or engagement bands, and also stacks well against contemporary pieces, adding a touch of early Deco elegance to any ensemble.