A single amethyst raised 3.2mm on a band of solid 10k gold, the purple reading warm against the yellow the way it does when the setting is plain. The gold has worn soft on the surface, a patina that only comes from decades on a hand.

We said yes to her for that pairing. A stone with this much colour on a substantial plain band is among the most wearable things in antique jewellery, and the aged gold gives her a warmth a new ring takes years to earn. Size 6, and she has the presence to go on a hand by herself.