Gorgeous Vintage 18K Two-Tone Gold Ring with Emerald-Cut Blue Spinel, 1947

The last of today's Friday trio - and the coolest of them. An emerald-cut spinel in that crisp, glacier blue, the colour of winter sky just after sunrise. The emerald cut is the quiet aristocrat of stone cuts: no fireworks, just long, clean flashes of light gliding across those stepped facets every time your hand moves. It is the cut you choose when you do not need to convince anyone.

And the setting matches her perfectly: solid 18K yellow gold with white gold accents framing the stone, so the blue sits in a cool silvery border before the warmth of the yellow gold takes over. That two-tone detail gives her an almost architectural look - clean lines all the way through - and it makes the blue read even icier. She was made in 1947, and that is exactly her charm: she looks modern, but she is pushing eighty. She would be as at home over a chunky knit sweater as she would be at a dinner table.

She fits like a size 8.5 US - a rare, generous size in vintage rings, so if that is you, this truly is your day. She sits low and comfortable on the finger, no snagging, just that long blue window of light.

She is in excellent condition with minor signs of age.