Are the wives of the late African miner Ali Giowatta once again on speaking terms?
One way to tell, say observers of the Tanzanian social scene, is to watch the supply of chrome tourmaline.
Giowatta, a Muslim, owned the world’s only two chrome tourmaline mines, both located in northern Tanzania. When he died in December 1980, a bitter battle for control of the mines broke out between his three wives. This feud brought the mines’ already sporadic production to a halt. The world had to depend on dealer backlogs of this gem, many of them in dealer-obstinate, Germany’s great cutting center.
When “chromes” began popping up in greater numbers in Nairobi, Kenya—East Africa’s chief gem trading city—back in 1984, it was assumed that domestic tranquility had been restored among Giowatta’s heirs. True, some argued that the pickup in supply had more to do with the fact that Tanzania, a socialist country, had opened its borders to its capitalistic neighbor, Kenya. But since the bettering of borders took place in 1983 without a resumption of chrome tourmaline plenty until a year afterward, closer harmony between Giowatta’s wives won credit for the improved flow of chrome tourmaline.
The harmony does not seem to have lasted long. Six months later, chromes were as scarce as before. Ever since, production of the gem has been sporadic, just enough to keep aficionados loyal and prices the highest paid for any tourmaline variety.
Those prices may seem baffling until one examines a fine chrome tourmaline. Top specimens of this gem exhibit a green that tempts confusion with fine tsavorite and rivals emerald. Even so, some dealers wonder how chrome tourmaline became the most expensive tourmaline in the world. The main reason is the gem’s East African origin and its reputation for somewhat pricey green gems.
A Clean Green
Like East Africa’s most widely respected gem, tsavorite garnet, chrome tourmaline is noted for a rich, bright, clean green that specialists insist is visually distinctive and has no real counterpart among other tourmalines. Indeed, novices are apt to mistake fine chrome tourmaline for fine tsavorite.
They shouldn’t feel bad, however. So do the experts. “The finest quality chrome tourmalines are only distinguishable from tsavorite with the aid of a gemological instrument such as a refractometer,” says Colin Curtis, Gemological Exploratorium Corp., Tuscan, Calif. (The refractive index of chrome tourmaline is usually 1.62-1.64 while that of tsavorite is 1.74).
Very recently, some superb stones have tempted comparison to very fine Colombian emerald. Curtis, an expert in East African gems who spends much of his time in Nairobi, reports that some newer material sports a “lovely bluish-green cast.” One such stone, on display at the recent American Gem Trade Association show in New York, resembled a spectacular emerald. Weighing more than 8 carats, its owner, New York dealer Issac Aharohi, Issac Aharohi Inc., was paid close to $1,000 per carat for it—the highest price we have heard of for a chrome tourmaline.
More commonly, very fine chrome tourmalines lean more toward the yellow than the blue end of the spectrum. But whether yellowish or bluish, chromium content is what gives them their bright, vivid color. Jewelers can even test for chromium content with a Chelsea filter. Under the filter, chrome-laden stones will show flashes of red or orangey red.
The Chelsea test is the main way dealers confirm the East African origin of tourmaline. Far more abundant green tourmalines from Brazil, Afghanistan, Maine and California are colored primarily by iron. So when these stones are subjected to a Chelsea filter test, their color remains green.
Even without a filter, dealers versed in tourmaline say “chromes” have a unique visual appeal. At their best, they boast an almost corrosively brilliant color. Of course, this uniqueness is reflected in their prices which generally, says Josh Hall of Pala International Inc., Fallbrook, Calif., are three times that of any other green tourmaline. Our wholesale price survey puts better-to-fine chrome tourmaline at $200-$400 per carat in sizes through 5 carats, as high as $800 per carat for exceptional 8-10 carat stones.
Caught in the Middle
Although chrome tourmaline is scarcer than tsavorite, it is not plagued by the size problem of that garnet. Chrome tourmaline occurs fairly frequently in sizes up to 10 carats while tsavorite is extremely hard to find in sizes over 2 carats. For this reason, top-grade tsavorites around 2 carats easily command $1,500 per carat sometimes closer to $2,000 per carat. (Comparable 1-carat stones fetch $800-$1,200 per carat.) Kindered-calibre chrome tourmalines around 2 carats will cost jewelers only $150-$200 per carat. That makes them one-tenth the price.
Yet demand for chrome tourmaline is probably less than one-hundredth than that for tsavorite. Why? “Jewelers don’t think of chrome tourmaline as a bargain compared to tsavorite,” says dealer Alex Bahnitarian, Alex Bahnitarian Inc., Englewood, N.J.. “They think of it as a very expensive tourmaline.”
This is not to say that chrome tourmaline doesn’t have its followers. Usage is increasing among jewelers and jewelry manufacturers. Virtually unknown before 1970, this tourmaline has now become the color standard for deep green in this gem. As said before, it has something to do with East Africa and the special aura that surrounds its gems, especially the green ones.
A word of caution is necessary here, though. Many chrome tourmalines do not possess the fine green we are describing and for which we are quoting prices. According to Curtis, only one of the two Tanzanian mines that produce this gem can be counted on for a fairly steady but thin flow of fine stones. It is called the Landanai mine and its stones are usually free of the brownish overtones that mar the tourmalines from its more productive sister mine.
Brownishness isn’t the only problem with chrome tourmaline. Often stones will be so saturate with green that they appear blackish or over dark. Unless price is your prime consideration, we advise steering clear of either brownish or blackish stones. “If you must compromise,” Curtis says, “go with lighter, livelier stones. The dark, somber-colored ones are almost impossible to sell.”
One last tip: Expect stones to be eye-clean. “A small wispy veil might be okay,” Hall says. “But stones shouldn’t be what you would call included.”
Please note: this profile was originally published in 1988 in Modern Jeweler’s ‘Gem Profiles: The First 60’, written by David Federman with photographs by Tino Hammid.
The 2.39-carat chrome tourmaline shown in the header is courtesy of Overland Gems, Los Angeles.