On this week's Freakonomics Radio, we meet a young Michigan couple who win a diamond at a charity event and then can't decide what to do with it. Sell? Set it in a ring? Or stash it in the laundry room and just keep fighting about it? We also hear from Edward Jay Epstein, who wrote a book about trying to resell a diamond, and we learn the strange, shady history of how diamonds have come to be as "valuable" as they are.