After the round brilliant cut, this is the most popular of all diamond cuts. The top of the diamond is cut into a square or rectangular with four beveled sides, not unlike an inverted pyramid. This style of cut was only created in the 1960s so it is a relatively new one, but has steadily gained popularity because of its distinctive shape. This cut is sometimes referred to as a square modified brilliant. Pricess cut diamonds combine the brilliance of a round cut diamond within its square or rectangular shape. This shape is not to be confused with a Baquette cut diamond though.
A princess cut diamond retains about 80% of the rough diamond from which it was cut and for this reason is slightly cheaper carat for carat compared to the round brilliant cut which contains only 50% of the rough crystal, and it is this 80% which makes this a popular shape amongst diamond cutters.
Grading a Princess cut
Currently the only two laboratories in the world who grade a princess cut diamond for light return are the American Gem Society, ot AGSL and the European Gem Laboratories-USA, or EGL-USA as well as the Accredited Gem Appraisers, or AGA.
The AGSL uses the symbol “0” to signify the highest grade while both the AGA and EGL use the symbol “EX”. What these signify is that these diamond have been deemed ideal. These grades have better light performance and are therefor more valuable.
Originally this cut consisted of 58 facets, but today there is a cut called the Quadrillion which consists of 49.