The £10 diamond that was worth a fortune


It’s every bargain hunter’s dream. The piece of costume jewellery that you pick up at a car boot sale or an antique store turns out to be the real thing.

That’s exactly what happened to a lucky British lady last month. The “Tenner” diamond, as it became known was purchased from a car boot sale at West Middlesex Hospital, London in the 1980’s, for a mere £10.

Believing it to be a piece of costume jewellery, the owner wore the ring on an almost daily basis, for decades. The owner of the ring assumed it wasn’t a genuine gemstone, due to the “filthy mount” and a lack of sparkle in the gem.

Believed to have been cut in the 19th century, it’s a mystery as to how the cushion cut 26.27ct diamond ended up at the car boot sale. It was only recently that the owner took the ring to Sotheby’s and a jeweller identified it as a diamond.

At the Sotheby’s auction, the ring went for a massive £656,750, well above the expected price tag of £350,000. Jessica Wyndham, Head of Sotheby’s London jewellery department commented that the cut of the ring was “slightly duller and deeper” than today’s designs.

“With an old style of cutting, an antique cushion shape, the light doesn’t reflect as much as it would from a modern stone cutting,” she said. “Cutters worked more with the natural shape of the crystal, to conserve as much weight rather than make it as brilliant as possible.”