Typical Princess Cut (Square Modified Brilliant)
A variation of the Profile cut by Arpad Nagy in the 1961; it is argued whether Basil Watermeyer of South Africa who invented the Barion cut or M. Weistreich of Belgium invented this improvement in the 1980s.  It is now one of the most popular cuts out of the fancy shapes. The creator of the Radiant cut claims that the Princess cut was stolen from his design. The cut combines a square Barion cut with a Round Brilliant. It contains a pavilion that is made up of a variety of angles due to a unique pavilion shape and variance in length and width, although the typical Princess cut is a square. Color and clarity can be disguised as well as a Round Brilliant with a well-proportioned cut.
A well-proportioned cut with Very Good Symmetry and Good Polish is recommended. A color grade of J and clarity grade of SI2 may be discernable by the naked eye.
Square (Length-to-Width Ratio of 1:1)
Table               58-78%
Total Depth    58-80%
Rectangular (Length-to-Width Ratio of 1.35:1)
Table               57-72%
Total Depth    58-69%
For more about AGS Labs take on Princess cuts see: http://www.agslab.com/marketingpdfs/CuttingGuideforPrincess.pdf
Variations: Ambar Diamonds Quadrillion, The Flanders Ideal Square, and E.F.D.'s PrincessPlus