A ring bought for a tenner at a car boot sale is revealed to be worth more than €400k

You never know what you might find at a car boot sale.

A large diamond ring is expected to fetch around €400,000 at a London auction in July almost three decades since it was originally bought. The jewel was purchased at a car-boot sale in the '80s where its owner paid less than £10, thinking it was just a costume jewel. The 26-carat, cushion-shaped, white diamond was an unknown steal at the Sunday sale and will go under the hammer at Sotheby's auctioneers in the summer. The rock was presumed not to be real because, apparently, 19th-century diamonds were not cut in the same manner as today's gems. The ring was brought into Sotheby's after a local jeweler told the owners that the ring could have substantial value and could sell for a juicy profit. The diamond was tested at the Gemological Institute of America where its astronomical value was revealed. The history of the ring before it was acquired at the car-boot sale, however, is unknown. The anonymous ring holders have a fantastic eye for a bargain and have been known to purchase designer dresses for cheap at sales over the years. The owners have been to quite a few car boot sales over the years and this one-off windfall has become an amazing find. The diamond ring will be offered as part of Sotheby London's Fine Jewels sale on 7 July. Main image via Sotherby's