Bonhams to auction Boucheron diamond tiara from 1924 collection

Bonhams is using six single-owner collections to make a pointed market statement: serious buyers are still chasing period diamond jewels with documented history, refined workmanship and names that carry weight. At the top of the June 11 sale in London sits a 1924 Boucheron diamond bandeau tiara, estimated at £200,000 to £300,000, with a 3.60-carat old brilliant-cut diamond at its centre. It is the kind of jewel that explains the current mood in the room: collectors want diamonds that are not only important, but identifiable, wearable and anchored to a story.

The tiara is an openwork bandeau built with scroll, quatrefoil and stylised olive-leaf motifs, all set with old brilliant, old single and rose-cut diamonds. A central pear-shaped drop softens the geometry, giving the piece the balance of a jewel made for a formal profile rather than a display case. Bonhams says it is being shown publicly for the first time since Boucheron in London made it just over a century ago, and that it was commissioned shortly before a family wedding in 1924. That combination of date, maker and occasion is exactly what keeps antique diamond jewels near the top of the market.

If the Boucheron tiara represents the appeal of grand period design, the circa 1910 Cartier seed pearl and diamond sautoir from Dame Nellie Melba’s personal collection speaks to a different kind of collector interest: signed jewels with Parisian cachet and Belle Époque lightness. Jean Ghika said the necklace reflects “the elegance of the Belle Époque,” a period associated with Cartier’s early use of platinum, and Bonhams has placed the signed Cartier Paris piece at £60,000 to £80,000. For buyers, that matters as much as carat weight. The jewel’s provenance from Melba, one of the era’s most recognisable voices, adds cultural capital to its ornamental one.

The auction’s other highlights show just how broad the appetite is across eras, but how consistent the taste has become. A Sterlé and Diringer ruby and diamond necklace from around 1935 converts to a bracelet and clip, a practical flourish that suits advanced collectors who value transformable design. A 5-carat Colombian no-oil emerald ring by Bulgari, a 20-carat Fancy Deep Brownish Greenish Yellow diamond ring, a 25-carat unheated Sri Lankan sapphire ring and a 5-carat Kashmir sapphire ring widen the field beyond white diamonds, yet each lot still depends on rarity, clarity of origin and strong house names.

Jennifer Tonkin said the sale features “no less than six distinguished and private single-owner collections” spanning antique, 20th-century and signed jewels. That mix, along with aristocratic pieces from the Sidmouth family, including a portrait diamond jewel of Emperor Alexander I of Russia circa 1810, gives the 119-lot sale the shape of a collector’s catalogue rather than a simple auction list. The message is clear: provenance is back in the foreground, and antique diamond jewels with design intelligence are commanding the sharpest attention.