The short answer is because GIA has elected not to put an overall cut grade on princess cut diamonds, as they do for rounds. While GIA reports on princess cuts (modified square brilliant) do contain aspects of cutting - polish and symmetry - this does not begin to tell the story of light performance. In terms of fire, brilliance and sparkle, there is a huge difference between mediocre princess cuts and ideal cut princess diamonds
The result is a market increasingly full of princess cuts with reports showing Excellent / Excellent (Polish/Symmetry), the highest grade for cut quality available in a GIA report for a princess. However, very few of them have top light performance! The reason for this is that cutters can retain more weight by making princess cuts with proportion sets that are less than ideal, while at the same time achieving the top grade from GIA for marketing purposes. The fact that many buyers equate Excellent/Excellent with a top overall cut grade perpetuates this trend.
Ideal Cut Princess Diamond
Poor Cut Princess Diamond
While AGS Laboratories does perform comprehensive cut quality analysis on princess cut diamonds
, their grading criteria is extremely demanding. Even the most skilled cutters find it challenging to meet all the requirements for AGS 0 Ideal Princess, and the market for them is a small slice of the overall market. Only consumers who have researched cut quality will even be aware that true Ideal princess cuts are available. Thus, the sad truth is that many manufacturers have determined that it is simply not economic to make top quality princess cuts.
Unless and until awareness and demand reaches a critical mass, it is unlikely that the status quo will change with respect to princess cut quality. However, there has been a small revolution in round diamonds that at least gives hope for the princess cut. The turning point for rounds corresponded to a confluence of events. Knowledge of the importance of optical symmetry and Hearts and Arrows patterning, along with the development of simple viewers to assess patterning and light return were important developments in the 1980s. The launch and rise of the AGS Lab and the popularity of the AGS 0 Ideal Cut diamond quality document in the 1990s served to propel awareness and demand in the market. These developments, combined with the explosive growth of information technology and e-commerce, have resulted in something of a sea change in the demand for ideal cut round diamonds. The GIA introduced their overall cut grade for rounds in 2006 and today the market is flush with GIA Excellent
, AGS 0 Ideal Cuts, and branded Hearts and Arrows Diamonds
. More and more manufacturers have developed expertise in making high performance rounds and have found the market ready to reward them.
Find Your Perfect Ideal Cut Princess Diamond
The internet has played a huge role in bringing important information about cut quality to the consumer. In years past, this “fourth C” was something of a de-facto trade secret. Through a combination of self serving nondisclosure and actual ignorance within the trade, the public was taught little about the importance of cut quality and its impact on beauty. Today, a treasure trove of information is easily accessible to shoppers through quality websites and diamond information forums. And third party review sites enable peer to peer communication of like-minded individuals often reinforcing the benefit of paying as much attention to the fourth C (Cut) as to the more easily understood aspects of color, clarity and carat.
Princess cut diamonds are quite popular today. But one has to wonder how much more popular they would be if cutting and light performance were closer to the top of the scale than what we see today in a market largely consisting of diamonds that can only be described as mediocre.