Lord Allnatt — The British Collector Behind the Allnatt Diamond
Lord Allnatt — The British Collector Behind the Allnatt Diamond
Alfred Ernest Allnatt (1896–1969), businessman and gem collector whose 101-carat fancy vivid yellow bears his name
Major Alfred Ernest Allnatt CBE was a British businessman, racehorse owner, and philanthropist whose mid-twentieth-century gemstone collecting brought one of the most important fancy yellow diamonds in the world into public knowledge. He acquired the diamond now known as the Allnatt Diamond in 1953 and commissioned its setting by Cartier in the form for which it became famous. The stone, a 101.29-carat cushion modified brilliant graded by GIA as Fancy Vivid Yellow, was sold by his estate at Christie's Geneva in 1996 and is now in the collection of the SIBA Corporation. Allnatt's name is preserved in the diamond's identity primarily because he was the first owner to give the stone significant public visibility through major exhibition and through the Cartier setting that became its trademark.
Career and collecting
Allnatt was born in 1896 and built his fortune in property development, publishing, and racehorse breeding through the inter-war and post-war decades. He was created a Commander of the Order of the British Empire (CBE) for his philanthropic work, which extended to art donations to the Louvre, the National Gallery, and other major institutions, as well as substantial bequests to British charitable causes. The honorific Lord sometimes attached to his name in popular references is informal; he held the rank of Major from his service and the post-nominal CBE, but no peerage.
His gemstone collection was assembled in the 1950s and 1960s through dealer purchases and private acquisitions, with the Allnatt Diamond as its most prominent piece. The collection also included other significant stones — coloured diamonds and major coloured stones — though none with the public profile of the yellow centrepiece. The collection reflected the broader post-war collecting wave, in which substantial private fortunes assembled over several decades were turned to acquisition of investment-grade stones, anticipating the institutional and corporate collecting that emerged from the 1980s onward.
The Allnatt Diamond
The Allnatt Diamond is a 101.29-carat cushion modified brilliant graded by GIA as Fancy Vivid Yellow with VS2 clarity. The stone is believed to have originated in the Premier Mine in South Africa, although early-twentieth-century provenance documentation is not complete and the original rough weight has been reported variously in different historical sources. The stone passed through the hands of several owners before reaching Allnatt in 1953; he commissioned Cartier to design and execute a setting in the form of a five-petal flower with platinum mounts, in which form the diamond is most often illustrated and exhibited.
After Allnatt's death the diamond passed through his estate and was eventually sold at Christie's Geneva in 1996, where it realised approximately $3 million. The buyer, the SIBA Corporation, subsequently submitted the stone for re-grading and re-evaluation by GIA, after which the diamond was recut very modestly to upgrade its colour grade from Fancy Intense to Fancy Vivid Yellow, the highest GIA designation for yellow body colour. The stone has been exhibited at major venues including the Smithsonian Institution and the Royal Ontario Museum, and remains one of the most photographed and most widely documented fancy yellow diamonds in the world.
The Cartier setting
The five-petal flower setting commissioned by Allnatt is itself a notable piece of mid-twentieth-century jewellery design. The diamond sits at the centre of an open platinum framework forming five symmetric petals, each set with smaller diamonds, with the yellow centrepiece visible from front and back through the open construction. The setting is designed to maximise light entry into the stone from all angles, intensifying the fancy yellow body colour and giving the diamond its characteristic glowing appearance even under low ambient light. The Cartier execution is a textbook example of mid-century high-jewellery setting practice and remains one of the diamond's defining visual features.
In the trade
Lord Allnatt's significance to the gem trade is as an example of the discriminating private collector of the post-war period — a buyer who acquired top-tier stones not for resale or short-term gain but for personal collecting, public exhibition, and eventual estate disposition. The Allnatt Diamond's continued public profile owes much to the documentation, exhibition, and care that followed his original acquisition, and to the Cartier setting that has accompanied the stone through every subsequent phase of its public life. The Allnatt name is now permanently attached to the diamond and is unlikely to be displaced regardless of future ownership changes.