Rapaport Magazine

Color Grading Redefined

Dubai-based International Diamond Laboratories unveils color-grading technology that opens up new possibilities.

By Michael Washburn
RAPAPORT... Is the eye a reliable tool for assessing color, one of the prime determinants of a diamond’s value? Not in the view of Peter Meeus, chief executive officer (CEO) of Dubai-based International Diamond Laboratories (IDL), and his colleagues.

IDL, which was established in 2007 and also has offices in Antwerp and Mumbai, has developed a Color Meter for its exclusive use. Although IDL grades diamonds of all sizes, the device may revolutionize the trade by making smaller stones, especially those of 50 points and under, easier to grade. The Color Meter, which was officially launched on August 30 in Mumbai — additional launches are scheduled to take place in Dubai on September 10, in Hong Kong on September 25 and in Antwerp on October 16 — could have a huge impact on India, through which so many of these smaller diamonds pass for cutting, polishing and shipping. By picking up the subtlest gradations of color — those that escape the eye of even the most highly trained and experienced gemologist — the Color Meter aims to perfect the accuracy of color grading.

“It has always been the ambition of everyone in the trade to have more consistency in grading,” says Meeus. The spot check that often takes place when a dealer sells a parcel of small diamonds, stating that the lowest in color is an “H” or an “I,” can now benefit from a new service: a color-only certificate. Meeus also points out that this method is more cost effective, with prices that go even below $10, as opposed to $50 and up for a regular certificate.

With the Color Meter, a diamond is placed inside the device, and controlled light is reflected though the diamond, which then passes through a filter. At that point the machine calculates the “color perception” for every defined illumination. The results of the Color Meter scan appear on the exclusive IDL Satbar, a specially developed two-dimensional graph providing scientific color definitions and classifications (shown above).

From the point of view of accurate grading, IDL scientists believe, there are many advantages here. When you look at a diamond in natural light, your measurements are subject to variables that might result in different grades from one viewing to another. Daylight varies from country to country and city to city, while the proximity and intensity of the sun varies from minute to minute and second to second. Atmospheric factors like clouds can change the way color appears. Another factor is “global dimming,” a gradual obscuring of the sky by pollution over the decades. Even with controlled light, grading color is by definition prone to human perception and error. Meeus and his colleagues believe that the Color Meter will produce only consistent results, as opposed to traditional grading methods that have a 25 percent to 30 percent rate of inconsistency.


The IDL Color Meter is not the first device that attempts to provide a more accurate color grade, but it differs from existing products. For example, manufacturers of the Sarin colorimeter stress efficiency above other factors, claiming on their website that it “grades diamonds in under five seconds.”

On the other hand, Meeus freely admits that when the IDL Color Meter grades at a high resolution, it is not fast at all. “It is a research device, not a marketing device. It requires a lot of maintenance, and it is very fragile,” he says. While Meeus, who is safeguarding the lab’s proprietary technology, will not go into too much detail, he maintains that “The methodology used by the IDL Color Meter to measure saturation is different. Furthermore, there is no use of a ‘set of master stones’ to determine borders between colors.” He claims that previously existing products do not offer as highly defined a measurement of saturation.


Meeus truly wants IDL to become widely known for revamping all aspects of the certification process. Besides offering what it promotes as an accurate color grade with the element of human error removed, IDL is the first lab to offer a secure digital platform, where customers can consult a soft copy of their grading document – the Digicert, a complementary service that comes with all IDL Certificates. Even before getting their diamond back from IDL, customers will know what its properties are, and it is even possible to follow the progress of the diamond from the time the lab receives it to its return. But most importantly, one can immediately forward the Digicert to downstream customers, thus accelerating the marketing of the goods. While important online services, such as verification of the authenticity of a grading report, have been available from the American Gemological Society Laboratories (AGSL) and other organizations, Meeus and his lab have gone further as part of what he sees as a larger trend. “The world is going digital,” he states.

True to its mission as a state-of-the-art lab sponsored by the Dubai Multi Commodities Center (DMCC), which aims to invigorate the region’s diamond industry, IDL is offering its certs in Arabic as well as English, with other languages to follow. Once again, this is a first among gem labs.


IDL has also sought to revolutionize the security of the entire process. If the customer so desires, the diamond can be sealed in a transparent, tamperproof container, bearing a label listing the 4Cs of the diamond. IDL promises to have the grading results ready within 48 hours of a diamond’s arrival at the lab, the idea being to “give the trade time to market its diamonds faster.” Besides Dubai, the lab has offices in Antwerp and Mumbai offering the same services and turnaround time.

Article from the Rapaport Magazine - September 2007. To subscribe click here.

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