When he published his monumental “Collecting and Classifying Coloured Diamonds” in 1998, Stephen Hofer outraged some dealers who specialize in these rarities by refusing to include a section on violet diamonds. In a note near the end of the book, he declared: “ . . . Violet does not occur as a bona fide colour variety in natural diamonds.”
Hofer had agonized over this omission throughout the writing of his book. Although he had seen diamonds with tinges of violet, he had never seen ones with color he could call “inherently pure violet.” Neither, he was willing to bet, had those fancy color diamond dealers who, nonetheless, were likely to be unhappy with his decision. As a gemologist well-versed in color science, he distinguished a hint of color usually seen in a diamond’s face-up position from a full-fledged hue observed in the rock’s bottom. For there to be a variety of diamond worthy to be called violet, at least one stone had to have a body color of unalloyed violet. Unless or until he found such a stone, Hofer felt duty-bound to leave out a section on violet.
“Since 1985,” he says in support of his controversial decision, “I had been measuring every diamond submitted to my lab for analysis with a colorimeter. Of the 20 or so so-called violet diamonds, all had measured too weak in saturation to be classified as such. Believe me, if I had seen just one stone that measured pure violet before I went to press, I would have added a part on violet diamonds.”
Instead, Hofer and his colorimeter both saw every so-called violet diamond as essentially or strongly gray and meriting descriptions as either “violet gray” or “violetish-gray” and not violet per se. Therefore, violet in diamonds was a secondary not a primary color. Most so-called violet diamonds were, in reality, a sub-species of fancy gray.
Until July of this year, that is. That’s when an Indian dealer sent Hofer a private collection of assorted fancy colors to evaluate in preparation for sale. One stone stood out as a crown jewel among the dozens he studied: a 1/2 carater that looked and measured a deep pure violet. “I nearly jumped out of my skin when I saw the stone,” Hofer says. “Finally, I could say there was such a thing as a violet diamond.”
Hofer believes this violet diamond is as singularly important as the 0.95 carat Hancock red diamond which fetched a mind-boggling $926,000 per carat at a Christie’s auction in 1987. “I can’t see this diamond selling for anything less than $200,000 per carat,” he rhapsodizes. If you want an idea of its color, turn to Tino Hammid’s shot of a diamond graded “grayish-violet” some years ago. The stone Hofer is talking about beats this stone by having no visible or measurable trace of gray.
The upshot: Yes, Virginia, there is such a thing as a violet diamond, but don’t ask Santa Claus to bring you one—not unless you’re willing to accept an IOU from him and then wait as many years as Hofer did to see the real deal. Better to settle now for a stone with a strain of gray.