GIA Color Grade: Fancy Vivid yellow      GIA Clarity Grade: VS2      Weight: 101.29 carats      Owner: SIBA Corporation

The Allnatt is named after it's former British owner, Major Alfred Ernest Allnatt. 
There are less than a dozen known diamonds that weigh over 100 carats and have a
strong yellow color, let alone a high clarity grade.  It is believed that the likely source of the
Allnatt is the De Beers mine in South Africa.