If your wife asks for a diamond and you get her this chair by Harry Bertoia, it’s a fair chance that she won’t be happy. But we think that she should be. Manufactured by Knoll, Bertoia’s 1952 Diamond Chair is made with welded steel rods in polished or satin chrome. The Italian-born designer said: “If you look at these chairs, they are mainly made of air, like sculpture. Space passes right through them.” As it’s probably not too comfortable to sit on steel rods, cushions can be secured to the chair with lock-snaps. Full covers can be stretched over the wire seat basket and secured with hooks.