Princess Cut Diamonds
The Princess cut is the second most popular cut shape for diamonds, next to a round brilliant. The face-up shape of the princess cut is classically square and the profile or side-on shape is similar to that of an inverted pyramid with four beveled sides. The princess cut hails from the 1960s, gaining popularity over the years as a distinctive alternative to the round brilliant cut diamond.
When compared to a round brilliant cut stone with the same weight and quality specifications, a princess cut will almost always be less expensive as it retains about 80% of the rough diamond compared to an approximate 50%. A princess cut with the same width as the diameter of a round brilliant will weigh because of the four corners which would otherwise have been cut off and rounded.However, while displaying the same high degree of brilliance, its faceting style is quite unique and completely different from that of a round brilliant. The Princess cut had its origins in the early "French" cut, having a step-modified "Double-French" or "Cross" cut crown and a series of unique, chevron-shaped facets in the pavilion which combine to give a distinct cross-shaped reflection when the stone is viewed directly through the table. Effectively, the Princess cut combines the high degree of light return of a round brilliant cut with a distinctive square or rectangular shape.
Accredited Gem Appraisers (AGA) and American Gem Society Laboratory (AGSL) and European Gem Laboratories-USA (EGL-USA) are currently the only labs that grade the Princess cut for cut. There is no universal definition of what measurements make an ideal princess cut diamond and many diamond manufacturers market ideal diamonds with differing facet patterns and angles as "ideal cut". In contrast to the AGSL, AGA, and EGL-USA the Gemological Institute of America (GIA) has stated that there is not enough industry consensus or empirical data to specify cut grading standards for Princess cut diamonds and to do so is at the risk of consumers who may be deceived by diamonds accompanied by unqualified Ideal or Excellent cut grades.
Over years of experience and learned observation, Jason Withers has set guidelines for the proportions which he believes creates the most beautiful princess cut diamond.
Princess Diamond Proportions Cut Chart
| Ideal Cut | Premium Cut | International Fine Trade Cut | US domestic Average Cut | Below Average Cut | ||||
| Cut classes | Class 1A | Class 1B | Class 2A | Class 2B | Class 3A | Class 3B | Class 4A | Class 4B |
| Table, % | 62-68 | 68.1-71 61.9-60 |
71.1-72 59.9-59.0 |
72.1-77.0 58.9-58 |
77.1-82.0 57.9-56.0 |
82.1-85.0 55.9-53.0 |
85.1-88.0 52.9-50.0 |
> 88.0 < 50.0 |
| Crown height, % | 9-10 | 8.9-8.5 10.1-11 |
8.4-8.0 11.1-11.5 |
7.9-6.0 11.6-13.0 |
5.9-5.0 13.1-15.0 |
4.9-4.0 15.1-17.5 |
3.9-3.1 17.6-18.5 |
<3 >18.5 |
| Girdle Thikness, % Word description and percentages |
Thin to Medium or Medium to Thick 1% to 3.0% or 1.7% to 5.5% | Thin to Thick 1% to 5.5% > more variance | Very thin to Very thick 0.4% to 7.0% | Extremely thin to Extremely thick 0% to > 7.0% | ||||
| Total Depth, % Determined by factors already considered above |
64-75 | 75.1-80.0 63.9-58.0 |
80.1-83.0 57.9-57.0 |
83.1-84.0 56.9-56.0 |
84.1-85.0 55.9-53.0 |
>85 <53 |
||
| Polish/Symmetry | Excellent to Good | Good or Fair | Poor | |||||
| Square range Length/Width ratios (Preferences only) |
0.95-1.05 | |||||||
| Rectangular range Length/Width ratios (Preferences only) |
1.5-1.75 | 1.49-1.06 1.76-1.99 |
> Class 3 < Class 3 |
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Princess Cut Diamond Ring Designs
Sadr |
Gamma Cassiopeia |
Reticuli |
