Priyanka Chopra Jonas wore the 11.16-carat fancy vivid “Bulgari Laguna Blu” diamond to the Met Gala on Monday, pairing the stone with a strapless black and white look from Valentino. (Photo credit/courtesy of Theo Wargo-Getty Image)

Originally acquired by Bulgari in 1970 and set into ring for a private collector, the pear-shaped stone will go up for auction during Sotheby’s Geneva “Luxury Week” (May 12-16). It is expected to sell for more than $25 million. (Photo courtesy of Sotheby’s)