Over the course of decades in the business, Richard von Sternberg has handled more than his share of remarkable gems. He’s built a long career in the colored gemstone trade, and worked with diamonds as owner of the U.S.-based Eight Star Diamond Cutting factory. In recent years, von Sternberg has championed couture-quality Ethiopian black opals. And today, in partnership with Bangkok-based gem expert Tom Banker, he’s turning much of his attention to something new—or perhaps rediscovered: vivid red pyrope-almandine garnet from Vietnam, a source with both pedigree and mystery.
Gary Roskin
Roskin Gem News Report
I Trust You, just so long as there’s a Lab Report
Von Sternberg had been growing tired of explaining the color origin of Ethiopian black opals to skeptical jewelers. “They concluded that there are no such things as Ethiopian black opals—that they must be all treated and smoked,” he recalled from a post-Tucson conversation with a jewelry designer. “I know that there are treated opals, but there is such a thing as natural Ethiopian black opals… They’re beautiful, and they’re spectacular.” And he has a nice inventory of them.
Still, he acknowledged the trust gap. “He said, ‘How do you know these are natural?’ And there he got me. I said, ‘Well, I trust my supplier.’ And he said, ‘I don’t trust your supplier. If you’re my supplier, I don’t know that I can trust you.’”
He should know that, after working so many years with diamonds at Eight Star. High quality color is going to need a lab report, just like a high-quality diamond. A lab report instills not only confidence but also trust in both the stone and the seller.
And so von Sternberg sent black opals to the labs, both the Gemological Institute of America (GIA), and American Gemological Laboratories (AGL). As for the reports, von Sternberg so proudly and confidently exclaimed, “Every single one of them said, ‘No gemological evidence of any treatment.’”
Photo by Gary Roskin
A New Chapter in Red
That experience with Ethiopian opals led von Sternberg to a new pursuit: intensely red garnets from northern Vietnam. So, he reached out to Tom Banker.
“I contacted Tom and said, ‘Find out—can you find out if there is such a thing as these garnets? The ones that look like brake lights?’”
Banker, a long-time veteran of the gem trade and one of the founding members of the American Gem Trade Association (AGTA), had already been tracking the source of this “new” red garnet. Throughout his career, he’s kept an eye out for unusual materials, and this one had his attention.
According to Banker, the garnets they’re sourcing come from the original mine near Luc Yen—a deposit long believed to be tapped out. “There’s another 300 carats on its way to me now,” he said. “And another 1,000 carats being reviewed.”
What complicates sourcing from Vietnam is the nature of mine ownership. “In Vietnam, you can’t really own a gemstone mine,” Banker explained. “But our source controls the mine.” He’s not convinced by the rumors that the deposit is exhausted. “They also say the mine is no longer producing that luscious blood-red color,” he said, “but I have reason to doubt it.”
A recent Gem Note in The Journal of Gemmology by Bear and Cara Williams of Stone Group Laboratories (Jefferson City, Missouri, USA) examined pyrope-almandine garnets from Lao Cai Province, Vietnam. While chemically similar, the differences in color and composition suggest these are from a separate deposit than the one Banker and von Sternberg are sourcing.
“I believe the garnet deposit referred to in the Journal is north of our mine,” said Banker, referencing Stone Group Laboratories’ ongoing research. This would correspond to the two mining areas Banker is familiar with.
From Brake Lights to Valentine
As one would expect, the quality of cutting is key to unlocking the garnet’s full potential. And so far, the cutting is, well…
“All the cut stones look to be trying to achieve 20% yield: heavy inclusions and bad color-orientation,” said Banker. “To make those garnets sizzle, they need to be properly cut from rough. My guess is only a 5%–7% yield for clean sizzlers.”
Five to seven percent? He says this so nonchalantly. Most of us unfamiliar with gem cutting might think those numbers are unreasonable. But those in the know recognize that proper cutting is the art that makes a gem “sizzle.”
Speaking to inventory, von Sternberg added his expertise: “Some are better than others. About half of the stones are a bit more included, so we’d use them for pendants or earrings. The cutting is decent. This is not Phil Youngman competition cutting, but it’s nice, and people are buying it.”
Banker is determined to work directly with the rough material. “I’m writing a proposal for the mine-‘owners’ to let me work with their rough, to brand the vivid-red garnet. Richard and I are calling it Valentine Garnet.”
Von Sternberg focuses on the sales side. And while this Vietnamese red garnet is still relatively unknown, that’s starting to change. “I just heard the whisperings about these things the other day,” he said. “And now, there’s even more talk. Yesterday, somebody told me, ‘Yes, I think I read something about them.’ So, it’s starting to happen.”
Whether they resemble rubies or brake lights, the duo’s aim is clear: bring these fiery reds to market with gemological backing and better cutting—so you can gift it to your Valentine.
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