An amethyst cabochon pairs deep violet with a restrained, vintage-style ring setting - and it is precisely that simplicity which lets the colour of the stone lead the eye. The cabochon cut does not scatter light into facets but gathers it into a uniform, saturated surface, where the violet shifts from warm purple towards a cooler shade depending on the light. Jewellery tradition links amethyst with calm and clarity of mind - which is why its presence in engagement rings stretches back centuries.

The choice of this particular piece came down to colour and clarity - a rich, even violet free of discolouration, which in this grade of stone is increasingly hard to find. Refined European sterling silver 925 forms its setting: the 925 fineness confirms the purity of the alloy, free from nickel and harmful additives. The French maker's mark struck on the piece attests to the origin of the metal and is legally protected at the French assay office.

For a city meeting, the ring works well with a camel roll-neck and a light trench coat - the violet of the amethyst brings neutral colours to life without disturbing their calm. Against cool grey or beige, every movement of the hand draws out the depth of the stone. The vintage character of the setting and the distinct colour of the amethyst together make a ring that needs no accompanying jewellery.