Today’s Fine Jewels sale in London exceeded pre-sale expectations to achieve £5,171,750 (est. £2,923,400- 4,183,200), with 80.1% of the lots sold. With an exceptional selection of contemporary and antique jewels and decorative accessories on offer, the sale was driven by competition from a broad spectrum of international buyers.

The sale was led by the newly discovered cushion-shaped diamond, named the ‘Tenner’ diamond, which sold for £656,750 (est. £250,000-350,000). 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 GIA as a genuine diamond.

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.”