Christie's specialist, Jean Marc Lunel, said the Archduke Joseph is prized because it boasts the highest quality of shape, colour and clarity that can be found in a diamond.
Those range from a mundane calendar of then-Undersecretary of State Marc Grossman to the often-talked about memo from the State Department's intelligence unit about former ambassador Joseph Wilson's 2002 trip to investigate claims that Iraq was trying to obtain uranium in Africa.