In 1962, Sydney DeYoung donated a bright pink pear shape diamond, weighing 2.90 carats, which originated from the Williamson mine in Tanzania. After his death, Sydney bequeathed an extremely rare red-hued diamond weighing 5.03 carats, one of the rarest and largest red diamonds in the world. In addition to these contributions, DeYoung has helped advise the Smithsonian in it’s quest to acquire other special gems.