Kim Kardashian's engagement ring from former husband Kris Humphries was sold for $620,000 at a Christie's auction in New York Tuesday, UsMagazine.com reported. An unknown bidder purchased the Lorraine Schwartz piece, which features a 16.21-carat center diamond and two 1.8-carat side diamonds. The professional basketball player waited to sell the ring until after their divorce was finalized this past May. The couple were married for 72 days when Kardashian filed for divorce Oct. 31, 2011. The reality TV star is now dating rapper Kanye West, the father of her infant daughter, North.