The original buyer purchased the so-called "tenner diamond" at a West London flea market and then wore it as a ring for decades. The buyer thought that gem was a next-to-worthless piece of costume jewelry, not a 26.27-carat white diamond.
At some point, the owner visited a jeweler who thought the ring might be valuable. It was taken to London-based auctioning multinational Sotheby's, which initially valued it at £350,000 ($446,000).
"The majority of us can't even begin to dream of owning a diamond that large," Sotheby's London jewelry department head Jessica Wyndham told a local news outlet. "The owner would wear it out shopping, wear it day-to-day. It's a good-looking ring. No one had any idea it had any intrinsic value at all. They enjoyed it all this time."
"It was a thrill to bring the hammer down on an object which has 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."
The ring was confirmed as a genuine diamond by the Gemological Institute of America, which believes it to have been cut in the 19th century. The original cutting was done to preserve size rather than emphasize brilliance, leading to a large but dull stone.
"I'm convinced the £10 ring was once owned by royalty or a person of great wealth, because it originates from the 1800s – before the discovery of modern diamond mines and a time when very few diamonds were available," Tobias Kormind, managing director of 77Diamonds.com, told The Sun.
"Several diamond dealers have already inspected this diamond to assess how large a modern cut diamond can be made from it. The new owner is likely to re-cut it into a modern diamond that will emit even more sparkle and potentially be worth a multiple of the Sotheby's estimate."
The stone was put up for auction on Wednesday, June 7. Bidding started at 240,000 pounds, passed 500,0000, and the rock finally sold for nearly twice the valuation to an international buyer.
