Sometime in the 1980s, a woman bought a piece of what she thought was costume jewelry for $13 at a London flea market. The ring she purchased turned out to contain a 26-carat diamond, and now it’s expected to fetch somewhere near its appraised value of $456 at a June 7 auction.
"We're used to people coming in with pieces from their personal collections, but this was exceptional,” said Jessica Wyndham, head of Sotheby’s jewelry department. For her part, the owner has chosen to remain anonymous, although CNN reports that she wore for decades before deciding to part with it.