Scientific experts try to uncover the secrets of the Hope Diamond, a 45-carat, deep-blue gemstone that has been housed in the Smithsonian National Museum of Natural History in Washington, DC, for the past 50 years. Ranked as the most valuable diamond in the world. 　　Why does it have a unique red afterglow? How did it come to be the shape it is today? And why is it believed by so ... (展開(kāi)全部)