"I naturally thought of Marilyn Monroe in her long gloves and pursey lips whispering "Diamonds Are a Girl's Best Friend""

Marilyn Monroe (1926-1962) was a popular movie star in the 1950s and early 1960s.  "Diamonds Are a Girl's Best Friend" was sung by Monroe in the film Gentlemen Prefer Blondes (1953). 

During this time, diamonds were one of the major exports from the Congo.