By Russell Shor

GIA unveiled more details of its proposed diamond cut evaluation system at GemFest Asia, held Sept. 20 at the Hong Kong Jewelry and Watch Show. The seminar featured GIA Vice President of Identification Services Thomas M. Moses and a panel discussion by three of the city’s top diamond dealers. GIA President William E. Boyajian offered an update on GIA research and activities.

Moses outlined how the GIA cut project began in 1989, with the creation of a computer-generated “virtual” diamond that was used in ray tracing experiments to develop metrics for brightness and fire. GIA researchers modeled more than one million proportion sets to create these metrics. They then began a series of observation tests using members of the trade, retailers, gemologists and consumers to validate the metrics. In total, more than 300 participants made some 70,000 observations of about 2,000 diamonds.

“This was the largest sampling of this type ever made,” he said.

In the course of the research, GIA created a standardized lighting system that reflects a variety of environments, including dealers’ offices, retail establishments and consumers’ everyday locations.

From the ray tracing experiments and observation tests, GIA found that a range of proportions, wider than currently accepted, could be used to create an attractive diamond which allows a much greater freedom in manufacturing. The Institute also used these findings to establish the foundation for a cut grading system for round brilliant cut diamonds. Moses explained that the new system will include five grades, because “during the observation portion of the study we found this was the normal number of categories that most human observers under controlled conditions can distinguish.”

Moses also noted that GIA will produce a cut grade reference system that will allow manufacturers, dealers, retailers and appraisers to predict a cut grade before their stones are sent to the GIA.

Targeting for around mid 2005, all GIA Diamond Grading Reports and Diamond Dossiers for round brilliant diamonds in the D-Z color range will carry the new grading system. The reports will also include a full explanation of the Four Cs.

Responding to questions, Boyajian noted that the Institute is not planning to increase prices for diamond grading services with the addition of a cut grade.

“We have kept the same prices for 17 years by making our lab operations more efficient,” he said, noting that screening stones for HPHT and synthetics has been added to the grading process, as well.

Boyajian also said reports issued during a certain period before the introduction of the new cut grade could be reissued without resubmitting the diamonds.

The three panelists, all from Hong Kong, were Ephrain Zion of Dehres International; Sandro H.D. Sze, director of manufacturing for Brilliant Trading Co.; and Tommy Tse of TSL Company. They agreed that the new cut system would have a positive impact on the industry because it takes a variety of international preferences into account.

“A universal system that truly represents the beauty of a diamond will be a benefit to the trade,” said Zion. “Previously, grading systems that focused on one narrow set of proportions benefited only one market.”

He also noted that preferences have changed over the years. “In the 1960s, for example, proportions were much wider [in variance] than is common today. And it was not rare to find round brilliant cuts with total depth of up to 68 percent, or as low as 55 percent. Later, diamonds with greater spread came into vogue.”

Zion noted that the Ideal Cut began receiving a lot of attention around 10 years ago, though it was truly popular in only one or two major markets. It also resulted in a loss (from cutting) of 58 to 60 percent of the original rough diamond. He concluded that, in the end, “We are selling works of art, excitement, glamour and miracles of nature.”

Sze noted that the increased flexibility of proportions will make certain types of rough more viable to be cut into round brilliants because manufacturers can save a few points and still achieve a good cut grade. Tse added that GIA “was taking a very objective approach with the highest integrity.”

Boyajian updated the audience on GIA activities for this year, noting that the Institute opened a new school in Mumbai and expanded education facilities in Los Angeles, New York and Hong Kong. He said 40,000 square feet is being added to the grading lab, which has seen an increase of 28 percent in items processed this year.

GIA’s top research priorities, he said, are synthetic diamonds, HPHT annealing of diamonds, cultured pearl treatments and corundum treatments. The Institute, he added, plans to update its pearl reports and enhance its colored stone reports.

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