For the last 14 years, Richard von Sternberg has claimed to hold the secret to producing the most precisely cut diamonds, but only recently have the experts begun recognizing the soft-spoken CEO of EightStar Diamond Co.
His credo is slowly gaining acceptance as gemologists, jewelers, and designers—including Steven Kretchmer and Paul Klecka—have been converted. Now the American Gem Society is revising its diamond grading system and has licensed a modified version of EightStar’s patented instrument for evaluating cut.
In 1919, legendary diamond cutter Marcel Tolkowsky devised a mathematical model for cutting a round diamond with 57 facets precisely aligned to maximize light reflection, so that all the light flowing into the gem would be reflected back with optimal fire and brilliance. Tolkowsky’s model later became known as the ideal cut, but verifying that the actual cut matched the model proved difficult for decades to come.
In 1977, Japanese businessman Takanori Tamura challenged a diamond dealer named Ken Shigetomi to create a device that could measure the actual light paths in individual stones. Shigetomi spent the next seven years developing a light-tracking instrument called a Firescope, which gauges the quality of an ideal-cut gem by generating a geometric picture of the light play inside the stone when a red light is shone into the diamond. When an eight-rayed star (hence the name of the company that Tamura founded) appears at the center of the stone, alignment is perfect and there is no light leakage. In 1990, Tamura introduced the Firescope to von Sternberg, who helped him establish an EightStar diamond-cutting facility in Northern California. Von Sternberg assumed control of the company in 1992, and four years later, he started to establish a dealer network in the United States.
While several other brands tout patterns of hearts or arrows as proof of superior cut, von Sternberg explains that those forms are produced by instruments that measure only the eight main facets of the stone, unlike the Firescope, which evaluates all 57 facets. “The facets must have a symbiotic relationship with each other,” says von Sternberg. “This is much more important than any formula. This is the true gemology.”
An EightStar cutter is trained for several months and can spend as much as an hour and a half aligning each facet on the top of the diamond with its opposite on the bottom, continually employing the Firescope to check his or her work. EightStar’s master cutter is von Sternberg’s wife, Alison, who says it takes three to four days to complete an EightStar stone compared to the three to five hours required for cutting what is known in the industry as a “hearts and arrows” ideal-cut diamond.
According to von Sternberg, the laborious process addresses the optical quirks of each diamond, but because of EightStar’s limited production, only a few hundred stones can be on the market at any given time.
“Nobody else works with a diamond’s individual optical characteristics,” says Gregory Sherman, a diamond appraiser based in New Jersey. “If you compare the brilliance, dispersion, and symmetry they achieve with even the best stones from prestige houses, it is like going to the Met versus listening to a high school brass band.”
EightStar Diamond Co.