Blue topaz, the dirt-cheap treated gem jewelers order in precise shades with eye-shadow names like “London blue,” has fostered high hopes for this species in the realm of pink. Can treaters coax pink from affordable golden topaz on the same scale they’ve coaxed blue from colorless?
They haven’t so far. But the gem market grapevine is abuzz with rumors that various kinds of precious (golden, peach and sherry-colored) topaz are being irradiated to produce pinks hues.
Treaters who specialize in blue topaz insist that irradiation has not worked to produce pinks. Even so, it is known that dealers experienced in home and office color-craft are heating precious topaz, especially flesh and salmon-colored stones, to remove interfering browns and oranges and render stones permanently pink. This method has been used for generations. What’s more, it has been done using heat sources like a gas flame that are no more sophisticated than a wino’s Sterno can. If you sell Brazilian pink topaz, chances are very good it has been heated.
Yet for all the talk of high and low-tech pink topaz, single-stone prices to jewelers for this variety in medium pure-pink shades seem astronomical in comparison to irradiated deep blue stones: roughly $250 versus $20 per carat.
The reason, dealers say, is limited supply. Not necessarily of precious topaz, but precious topaz with an essential coloring agent: chromium, the same trace element responsible for red in ruby. Relatively few stones from Brazil, the principal source for what topaz, have this trace element in enough quantity of pink what dealers there call a “pinking.” However, gem-rich Pakistan has great promise as source for pink topaz—much of it so purely pink to begin with no enhancement is needed.
Brazilian Blush
Although the colorless topaz that can be turned aqua blue is found throughout the world, the topaz that can be turned pink seems only to come from Brazil, much of it from one place there, Oro Preto.
According to dealers and treatment specialist Pete Flusser of Overland Gems, Los Angeles, stones most responsive to heat are the intense fiery-golden kind known as imperial topaz. “I’ve never seen a piece of imperial topaz that didn’t turn pink,” he says. Unfortunately, this material is so expensive that it doesn’t pay to treat it. So dealers experiment with less costly material.
At present, such experimentation is pretty much hit or miss. Dealers, says John Koivula, chief gemologist at the Gemological Institute of America, Santa Monica, Calif., look for affordable crystals, usually ones that show a pink color core surrounded by brown and orange when viewed down the C-axis (length). That’s a pretty good indicator of convertibility to pink. What these dealers are seeing, Koivula explains, are “concentration zones of chromium coloration.” Heat burns off the brown that masks these zones and leaves stones anywhere from sweet lilac to deep, reddish violet.
When lilac, far more often the result than reddish violet, stones resemble the fine bright kunzites seen recently from Afghanistan. But we have yet to find well-cut medium-lilac topaz priced under $200 per carat like jewelers in 38-carat sizes; $250 to $300 per carat is more like it. If jewelers don’t mind the mild presence of orange and brown to give salmon and flesh pinks, they’ll probably be able to buy such sizes in the $150 to $200 per carat range, perhaps a tad cheaper. (We are not talking of medium-violet or golden colors which, although they sometimes sport traces of pink, do not qualify as pink topaz; such stones are readily available for between $50 to $100 per carat. Medium-peach colors with hints of pink can be found for $125 to $175 per carat.)
Given $200-per-carat minimum prices for truly pink topaz from 3 carats up, it is easy to see why this stone is not more available and therefore popular. For demand to surge, dealers must be persuaded to take more chances heating pink-prone topazes. But the risks are high. Heating can fracture commonly encountered carbon dioxide inclusions. Further, many stones may not have enough chromium to go beyond the pale. So selection of heating candidates must become more scientific. Koivula believes this may happen as dealers discover and subject candidate crystals to premium content analysis before “pinking.” This involves use of sophisticated technology such as neutron activation or microprobes that measure amounts of trace elements.
Pinks from Pakistan
Of course, if topaz finds in Pakistan prove significant then heating of precious topaz to create pink stones may become unnecessary. According to Cap Beesley, President of American Gemological Laboratories in New York and a United Nations consultant to Pakistan’s gem exploration venture, the country has been producing “all-natural purplish-red stones that are unique in color and intensity.” Priced by the government as high as $2,000 per carat, these magnificent gems appeal only to a handful of collectors.
Although far less expensive, Pakistan’s more abundant brownish pastel-pink and apricot-orange topazes are still priced way above current market levels for comparable Brazilian stones. “The prices reflect the tremendous startup costs of full-scale exploration and mining in Pakistan,” Beesley explains. “Nonetheless, they are a bit off the wall.”
Officials of Pakistan’s government-run gem sales division try to justify higher prices for their stones because they are untreated. But this may not be a matter of choice. Beesley believes the Pakistani might be trying to make a virtue of a defect. “From what I understand, their orangy-brown stones don’t turn pink when subjected to heat, perhaps due to the presence of vanadium along with chromium,” he says. “So suddenly all the topaz is being proclaimed free of treatment.”
Whatever the case, lack of enhancement is not liable to mean much to dealers, manufacturers and retailers, accustomed as they have become to heating and irradiation, especially of topaz. Nevertheless, the best of Pakistan’s pinks are in a class by themselves and merit some sort of premium on that basis—unless geologists there hit upon some fairly significant pockets. Beesley feels confident they will. “The pink stones seen so far come from a hillock in the middle of a flat alluvial plain,” he explains. “The next stage of exploration will take teams of mining engineers into the mountains that surround this area. If the vein continues, Pakistan could some day become equal in importance to Brazil for pink topaz.”
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 51.46-carat certified natural pink topaz in the header image is courtesy of Casmira Gems, Chicago.
