Diamond Grading with Bells and Whistles

Electronic diamond-grading machines are becoming a staple at the counters of more and more jewelers, especially now that manufacturers have added consumer-grabbing features. Retailers can put on a high-tech show when selling a diamond and give consumers more confidence in making their selection. The devices are particularly useful for non-gemologist jewelers dealing with knowledgeable customers.

The key manufacturers – Sarin Technologies, which makes a diamond-proportion meter; Gran Computer Industries and Austron Corp., makers of color-grading units; and Adamas Gemological Laboratory, which makes the high-priced, high-tech Adamas Advantage – are turning their attention from the diamond industry to retailers. One reason is simply that retailers represent a much bigger market for their machines. Manufacturers say about half of their sales go to retail jewelers.

A sales tool. The Brilliant-Eye unit, manufactured by Sarin Technologies of Israel, measures a diamond’s proportions with a tiny camera and displays an enlarged image on the jeweler’s computer. Retailers can use the display to show the quality of the diamond cut to customers. A printout is created with actual-size top and side diagrams of the stone, giving its measurements and a cut grade.

“It’s a multimedia show for jewelers to use both as a sales tool as well as a measuring and grading device,” says Fred Fisch, Sarin’s New York representative. Sarin introduced the Brilliant- Eye for retailers just over a year ago, five years after launching its larger Dia-Mension unit for the diamond industry.

Brilliant-Eye units are preprogrammed to American Gem Society cut-grade standards; units with changeable cut-grade standards cost extra. Fisch says consumers can use the printout to comparison shop before buying. They can also be sure they’re getting the same diamond back if they take it in for remounting.

The basic Brilliant-Eye sells for less than $6,000 (the label printer and computer imaging system are extra). But Fisch admits that it probably won’t catch on with mass merchandisers or discount retailers who sell off-makes. “This machine will only publicize a poorly made diamond,” he says.

Larger units for the diamond trade, which can measure many mounted stones at once, sell for $11,000 to $22,500. Since their introduction six years ago, these units, which can measure and cut-grade a diamond in 15 seconds, have transformed diamond manufacturing and sped up diamond grading by eliminating the need for manual measurements. Diamond manufacturers use them to virtually mass-produce cut grades, which allows them to segregate goods for the U.S., European, and Japanese markets much more easily.

All the major gem labs use these units to measure diamonds, but none relies on them for automated cut grades. “The Sarins don’t measure finish and symmetry and can be thrown off by dirt or foreign objects on the diamond’s surface,” says Peter Yantzer, director of the AGS Gemological Laboratories. “That’s why we still use human graders to do our cut grading.”

Color-grading machines. These reservations aside, Sarin’s units have won universal acceptance because they’re accurate if used correctly. More controversial are color-grading machines, which still have a way to go to meet that standard.

Many gemologists believe they never will. When it comes to diamond grading in the labs, the “eyes” still have it. Every major gem lab employs human graders to color-grade diamonds because machines are more easily fooled. The human eye and color-grading machines sometimes “see” color differently, says GIA research chief James Shigley. That viewpoint is widely shared among gemologists.

Lab executives and gemologists agree the newer models are more accurate than the original Okuda Industries machines that appeared 20 years ago. But they insist the machines still can be fooled by a number of variables: highly fluorescent diamonds, brown body color, dark inclusions, or stone position. “This is why we can’t use them in gemological labs,” says Jerry Ehrenwald, president of International Gemological Institute Labs in New York. GIA and other labs use them for testing but never in actual lab work.

Manufacturers of the two most popular color-grading machines, Gran Technologies of Israel and Austron Corp. of Santa Clarita, Calif., say they’re working to overcome such shortcomings and claim to be accurate to within a half or a third of a GIA color grade. Both companies want to bring their machines more in line with how people see diamond color. To that end, manufacturers try to calibrate their machines according to GIA’s color-grading standards. “Of course we try to match the GIA’s grading,” says Paul Gran, president of Gran Industries. “After all, it’s the industry standard.”

Both the Gran and the Austron units now have improved centering devices to hold the diamond in a stable position and reduce the possibility of erroneous or inconsistent readings. Both are distributed by Kassoy Inc. of New York. Austron president James Austin claims his unit, which costs just under $4,000, in some ways is more reliable than human graders, who measure only the amount of color in a diamond and not the color itself.

Gran’s newer units, which cost about $4,500, are compatible with the Brilliant-Eye, so retailers can issue instant color grades with their proportion reports. “What this does is offer retailers who aren’t gemologists a way to compete and survive,” says Gran.

All diamond color-grading units use a spectrophotometer to measure the absorption of light from a diamond’s body color. Despite their limitations, many diamond dealers swear by them – more than half of the old Okuda machines reportedly are still in use. Dealers say such machines are the only way to grade large numbers of diamonds quickly and economically.

“Everyone sends caraters out [to the labs] for certs today, but it’s too costly and time-consuming to individually grade big parcels of smaller stones,” says one Indian diamond dealer working out of New York.

Dealers understand the shortcomings of color-grading machines but say there’s no problem if you know what to look for. “All we have to do is pull out highly fluorescent stones and the browns,” says one dealer.

Beyond color grading. Wider in scope and pricier ($9,500 to $10,250) is the Adamas Advantage System, manufactured by the Adamas Gemological Laboratory of Brookline, Mass. Besides color grading, the Adamas unit can detect diamond synthetics and treatments. Its creator, Martin Haske, says the device “can replace De Beers’ DiamondView [synthetic detector], color-grading machines, and a spectrometer. In addition to reading diamond color, it can detect damage done by irradiation and traces of the nickel catalyst used in synthetic diamonds.”

Lee Davis of Seng Jewelers in Louisville, Ky., uses an Adamas Advantage unit to color grade stones and verify that the diamonds are natural. “Customers like to see the machine verify our diamond grades,” he says. “It makes them feel more confident that they’re getting more than just one person’s opinion.”

Like his colleagues, Haske has added consumer-oriented reports for retailers to use as a sales tool. Haske, whose clientele is evenly divided between retailers and gem dealers, is now working to add a ray-tracing facility to develop a cut grade based on light output, not a preordained set of proportions. “Of course it will be simpler than the GIA’s ray-tracing equipment, but it will work on the same principle,” he says.

While the manufacturers of diamond-grading machines claim progress in grading color and cut, the final frontier of automated diamond grading is clarity. Nearly everyone is working on a clarity unit, but no one has been able to develop a reasonably priced machine that can distinguish between inclusions and their reflections.

Gran says he’s made a “substantial investment” in developing a clarity-grading machine and vows to have one on the market someday. “The technology does exist, but we have to figure out how to make a reliable unit that’s affordably priced,” he says.

The machines are useful for non-gemologist jewelers dealing with knowledgeable customers.