A 26-carat diamond ring picked up at a car boot sale for a tenner ($15) 30 years ago is now valued at up to £350,000 ($455,631).
Who knows what could be lurking at your local car boot sale...
The owner believed it was costume jewellery all that time and only had it valued on a whim.
The ring dates to the 19th century and was overlooked due to its dull mount and unfashionable cut.
As Jessica Wyndham, head of jewellery at Sotheby’s, explained: "With an old style of cutting, an antique cushion shape, the light doesn't reflect back as much as it would from a modern stone cutting.
“Cutters worked more with the natural shape of the crystal, to conserve as much weight rather than make it as brilliant as possible."
It will auction at Sotheby’s London in July 7.
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