£10 car boot diamond sells for six figures at Sotheby’s

A diamond that was bought for just £10 at a car boot sale has made an incredible £656,750 at Sotheby’s recent Fine Jewels sale in London.

The newly discovered cushion-shaped diamond, name the ‘Tenner’ diamond, led the sale which achieved a total of £5,171,750, with just over 80% of the lots sold.

The ring was originally purchased in the 1980s from a car boot sale for just £10, when it was assumed to be a decorative costume jewel. The ring was recently confirmed by the Gemological Institute of America (GIA) as a genuine diamond.

With a broad spectrum of international buyers, another highlight of the sale was a Cartier diamond brooch worn by Margaret Thatcher on a number of high-profile public occasions, including the day she offered her resignation as Prime Minister to The Queen. With its unique geometric chevron design, the brooch piqued the interest of buyers to achieve £81,250 (est. £25,000-35,000), proceeds of which will be donated to the Endeavour fund – a charity that supports the recovery of wounded, injured and sick servicemen and women.

Jessica Wyndham, Sotheby’s Head of London Jewellery Department, said, “It was a thrill to bring the hammer down on two objects which have been the subject of so much interest and attention over the last few weeks and to see that attention translate into such strong bidding competition. Both were exciting punctuation points in a sale where the huge variety of material on offer was matched by a broad mix of collectors internationally- driving prices well above estimate on so many occasions.”