Recently the Fancy Color Research Foundation (FCRF) provided valued reading information on the FCRF on Inner–Grade, Dispersion, and Undertone (I.D.U) Grading Standard.
A fancy color diamond is the most precious stone unearthed in the world. Its endless visual appearances make it the most complex gem to evaluate and price in the luxury space. Today, the vast majority of fancy color diamonds are submitted to the GIA lab to obtain a report confirming their natural origin and gemological characteristics.
Without this grading, fancy color diamonds cannot be fairly traded. GIA grades on the report relate only to the gemological aspect and do not reflect the visual qualities that make a color diamond attractive and valuable. Consequently, since aesthetic aspects are not addressed during the GIA lab examination, many diamonds sharing the same grades will exhibit numerous visual differences that dramatically impact their market price.
The fancy color diamond market is undergoing significant evolution, driven by a surge in demand from jewelry enthusiasts for these rare gems. This growing interest has seen the rarest of diamonds commanding prices of millions of dollars per carat. In response, manufacturers are vying for rough diamonds, investing meticulous effort to enhance each diamond’s appeal.
As part of their strategy to attain higher prices per carat, wholesalers are now more attuned to the visual nuances that are increasingly sought after by consumers. Over time, a broad consensus has emerged around the qualities that enhance a color diamond’s attractiveness and those that might warrant a discount.
Experienced diamond professionals, who have traded a significant number of fancy color diamonds over the years, develop a keen understanding of the three main visual features and their impact on price. Drawing on their familiarity with similar diamonds from a large number of previous transactions, they are able to intuitively appreciate any visual combination and estimate a price for almost any color diamond they encounter.
The vast majority of fancy color diamonds pass through jewelers before reaching the end client. Unlike diamond dealers, jewelry salespeople encounter a limited number of fancy color diamonds during their careers and lack the ability to recognize all the visual nuances that impact their price.
Consequently, sales associates gravitate towards the more familiar and conventional terms from the colorless diamond world, such as Polish, Symmetry, Clarity, and Fluorescence, which do not address the aesthetic aspects of a fancy color diamond in any way. This leaves jewelers unable to explain the price differences between any two diamonds with the same report.
Historically, the diamond and jewelry industry lacked mechanisms for transferring practical knowledge from wholesalers to jewelers, leaving key visual qualities that influence fancy color diamond value unexplained. Recognizing this gap, the Fancy Color Research Foundation initiated in recent years a broad effort to standardize visual grades, akin to how the GIA has shared knowledge on colorless diamonds.
In 2012, the IDU grading methodology was introduced in professional literature and quickly gained traction among jewelry brands and independent jewelers. Following this widespread adoption, the FCRF secured the rights to this methodology, aiming to establish a common language that enhances engagement between jewelers and their collectors.
In this section, we will detail the visual criteria, Inner–Grade, Dispersion, and Undertone, collectively known as the IDU. (Readers, This, IDU will update soon.)