Please click on image to expand. This rare exhibit of 7 of the world's most famous diamonds was made possible by the Smithsonian Institute, The Steinmetz group and the Gemological Institute f America. The big one with pure coloration is the De Beers - millennium Star. Which is the world's second biggest top colored diamond. Flawless both internally and externally, pear shaped diamond. The others are tinted a little as impurities and defects replaced some carbon atoms during growth. [ Image Source ]