A moonstone cabochon catches the light and reveals a blue flash that shifts across the surface with every movement of the hand. This effect, known as adularescence, shows best when the stone turns towards a window. The simple, minimalist setting in rhodium-plated 925 silver never competes for attention - this is a solitaire design that works equally well as a right-hand ring or as an engagement proposal.

We assess each stone before it is set, looking at the depth and clarity of its blue flash, so only pieces with a vivid play of light make it into the ring. Good moonstones are increasingly hard to find today, and silver rises in price year on year, which makes this purchase a sound one right now. The rhodium on the surface is hard and scratch-resistant, so the ring's shine does not dull over time. The metal is refined European silver 925, pure and free of harmful additives that could irritate the skin. The piece is stamped with the French maker's mark, which attests the origin of the silver. In old beliefs, moonstone was linked to intuition and inner balance. This symbolism suits an engagement ring well.

For a meeting in town, the ring pairs well with a roll-neck and a trench coat in cool grey - the stone's blue flash lifts a muted outfit without ever looking overdone. Its small, elegant form sits lightly on the hand and makes it easy to wear every day, including at work. In winter it suits a wool coat, in summer a linen shirt in natural tones. This is a ring that shows a new face of the stone with every movement of the hand.