A swimming-pool blue zircon sits at the centre of this ring. Among the most fiery stones available to traditional jewellers, zircons were long regarded as second only to diamonds for their sparkling lustre and dazzling dispersion, and treasured in their own right for the range of beautiful colours they exhibit. The square step-cut of this stone is an unusual choice for zircon, which is usually cut as a round brilliant to maximise its scintillating optics. The effect instead emphasises the remarkable body colour of the stone, and hints at a 1920s date, when jewellers began to favour clean geometric forms over the refined ornamentation of previous eras. The style of the surrounding diamonds is known as the ‘single-cut’ or ‘eight-cut’, with the same proportions as the modern brilliant-cut, but with fewer facets. The effect is perfectly keeping with the simple, geometric look of the central stone. The shank is stamped ‘18ct plat’ for 18 carat and platinum.