You know it’s a thing when the world’s biggest pop star is doing it.
Gone are the days when a gargantuan, brilliant-cut white diamond was the height of engagement ring chic. A tennis bracelet? Heaven forbid.
But in the face of the lab-diamond onslaught, discerning shoppers are turning to something harder to reproduce: the antique, colourful and genuinely rare diamond.
In 2025, Taylor Swift sent her fans into a frenzy when her then fiancé, footballer Travis Kelce, proposed with an old mine-cut diamond in a new setting, designed by Artifex Fine Jewelry.
Old mine-cuts are the hand-cut ancestors of today’s precise brilliant cuts: chunky facets, irregular proportions and a softer glow. Increasingly in demand, they are the antithesis of replicable, machine-cut precision.
“When it comes to old-cut diamonds, each one is inherently unique,” New York designer Mindi Mond told Rapaport, the respected diamond journal.
Henry Bailey, head of jewellery at Christie’s London, tells the FM that the shift to rare diamonds is discernible.
“Collectors at auction are increasingly seeking out less readily available diamond jewels, such as old-cut diamonds, antique diamond jewels, or diamonds set in ‘signed jewels’ produced by the world’s great jewellery houses and designers,” he says. These designers include Cartier, Van Cleef & Arpels, Bulgari and JAR.
“Interest in these jewels has grown globally over the years, as an increasing number of buyers — including younger collectors — recognise the rarity of these pieces and the relatively limited supply available,” he says.
Deliciously, collectors aren’t afraid to fight over the best either. A 1929 Van Cleef & Arpels diamond “tie” necklace sold for $3.6m in 2024, as a bidding war among the seven interested parties saw the price spike to three times the original pre-auction estimate.
That tie is one of many pieces with provenance shooting the lights out on the secondary market. They may be just jewellery, but their design history is so unique that no-one can replicate them by manufacturing another batch.
“Jewellery has always been prized for its very personal, talismanic and emotional qualities,” says Bailey. Add provenance and story, he says, and you often get “greater interest, competition, and higher prices”.
Scarcity, in other words, is sexy. Add a fancy diamond to the mix and you’re really cooking.
“Fancy”, in diamond-speak, isn’t just another adjective. It means coloured diamonds — blue, pink, red, orange and green. In the flesh, the best are freakishly beautiful.
Their colours are quirks of nature. Boron produces blue; nitrogen is behind yellows and many oranges; distortions in the crystal structure create most pinks and many browns; and natural radiation turns diamonds green.
South Africa is tops when it comes to blue diamonds. The Cullinan mine near Pretoria, owned by Petra Diamonds, is the most important source of rare blues. In 2022, the 15.1-carat De Beers Cullinan Blue sold for $57.5m.
Auction buyers, it turns out, go mad for colour.
In May, Christie’s sold the 5.5-carat fancy vivid blue-green Ocean Dream diamond for $17.3m, while the record for the most expensive diamond ever sold at auction still belongs to the 59.6-carat fancy vivid pink CTF Pink Star, which fetched $71.2m at Sotheby’s Hong Kong in 2017.
“Demand at the top level for coloured diamonds is strong,” Bailey says. And while synthetics have hit smaller stones and the mass market, at the top end “the finest diamonds and jewels represent something genuinely scarce and cannot simply be replicated”.
This is all part of the new sales pitch that natural diamond producers are mounting — not bigger or shinier, just impossible to get your hands on.
