A cabochon-cut black onyx opens this ring with a deep, matte black that doesn't reflect light the way faceted stones do, but absorbs it instead. Such a smooth surface catches the eye at once, even without shouting in colour. Onyx has long been associated with strength and endurance, and is sometimes seen as a symbol of confidence - here that symbolism sits well with the role of an engagement and promise ring, worn as a mark of a decision, not just an adornment. The modern, simple band doesn't draw attention away from the stone, and the medium size means the ring sits securely on the hand, without weight.

For this piece we chose an onyx with a uniform, deep colour and a clean surface free of discolouration - these are what determine the stone's quality, not its size. Silver and good stones get more expensive year on year, so it's sensible to decide on a purchase like this now. The stone is set in refined sterling silver 925, pure and nickel-free, so the ring doesn't irritate the skin even with everyday wear. A rhodium layer protects the surface from tarnishing and keeps its shine over time, and the European care in craftsmanship shows in the even finish of the setting. The piece is stamped with a maker's mark registered at the French assay office, which attests the origin of the metal.

Styled for the office, this ring pairs well with a smooth shirt and a blazer in muted, cool grey or navy - the black of the onyx doesn't get lost against such tones, it only gains in presence. It also works well with a simple sweater and tailored trousers, when you want to keep the styling calm and modern. A hand wearing this ring looks well-groomed and confident, which suits formal occasions. This cabochon black onyx set in rhodium-plated 925 silver combines simplicity of form with the stone's distinct character.