The deep purple of the faceted amethyst catches the light in fine glints, and right beside it a single cubic zirconia sparkles, offering a small complement to the main colour. This ring, with its modern, understated silhouette, sits well on the finger and doesn't overwhelm the hand in movement. The form nods to its nature as a promise ring - a simple band keeps the focus on the stone rather than on ornament. Amethyst has long been associated with calm and clarity of mind, which suits the character of this kind of ring well.

For this piece we chose an amethyst with a deep, even purple hue and a clear interior free of cloudiness - it was this colour and clarity that decided the choice of stone. Good stones of this quality are becoming harder to find, and the prices of silver and precious metals keep rising, so buying now makes sense price-wise. It is set in refined sterling silver 925 of European quality, coated with a layer of rhodium that protects the surface against tarnishing and loss of shine. The alloy is free of nickel and other harmful additives, so the metal doesn't irritate the skin. The metal also bears a maker's mark registered with the French assay office, attesting to its origin.

This ring works well in the evening, worn with the little black dress and a silk wrap or a simple silk blouse - the purple of the amethyst stands out clearly against black and draws the eye with every movement of the hand. It's worth skipping other hand jewellery then, so the stone stays the centre of attention. It also suits understated, dark outfits for special occasions, where one striking detail matters more than an abundance of ornament.