Those wanting to pop the question in an unusual fashion may consider a trip to Chicago’s Field Museum where, for a $350 fee, the staff will place your engagement ring inside a case in the Grainger Hall of Gems. The service is proving popular. The Field is currently hosting The Nature of Diamonds, an exhibit that explores the history and beauty of the popular gem. The 128.54 carat Tiffany Diamond and the 407.48 carat Incomparable Diamond are on display.