Dealers old enough to remember the golden age, nearly 30 years back, when Burma ruby was so plentiful there was no need to sell any other variety have had to make a painful peace with stones from substitute sources, mainly Thailand and, more recently, East Africa and Mozambique.
Those too young to remember are more skeptical. Were the best Burma rubies of yesteryear really so superior? Or were they, like so many other bygones, an over-sentimentalized fantasy?
To decide which, researcher David Federman, award winning journalist with Modern Jeweler magazine, and self described yuppie-generation gem market specialist, spent a couple of days making cold-eyed comparisons of better-to-fine classification Burma and Thai rubies, hundreds of carats of them, ranging from melee (very small stones) to 5 carat sizes.
His conclusion was, as traditionalists assured him it would be, that Burma ruby has no peer. Despite color bolstering from heat treatment, Thai rubies generally flunk side-by-side savorings with the Burmese variety.
Burma ruby’s vast aesthetic edge became most apparent during a visual onslaught in the office of a New York gem importing company. One of the firm’s principals brought out box after box of better-to-fine Burmese and Thai stones, he could see amazing, often overwhelming, differences in color and appearance.
Although difficult to put into words, the final difference came down to “sex appeal.” For the most part, the Burma stones had a softer, slightly pinker red with lighter tones. The Thai stones, by comparison, seemed harder in color, darker in tone and prone to annoying grays and browns. What’s more, when held at a distance, the color of the Burma stones seemed more pronounced.
Admittedly, all of this is subjective. Quite possibly, some of the stones designated “Burmese” hailed from the increasingly important ruby belt running across Afghanistan and Pakistan. Others may have been pretenders from Kenya, Tanzania and even Thailand itself. Nevertheless, the overall experience made as profound an impression as any in this researcher’s many years of jewelry market coverage.
Gemologists say such exalted feelings about the Burma ruby are hardly surprising. Nature has showered some distinct blessings on this breed.
The Fluorescence Factor
If no longer entirely synonymous with a specific origin, the term “Burma” is still synonymous with ideal beauty in a ruby. Whether a rich solemn intricate red called “pigeon’s blood” or a more bubbly pinkish color called “cherry red.” Burma rubies at their best have a distinctive glow,
especially in broad daylight. This glow, explains eminent gemologist Robert Crowningshield of the Gemological Institute of America, Carlsbad, CA, is the direct result of fluorescence. When ultraviolet rays, a strong component of sunlight strike fluorescent stones, they excite atoms within. This reaction adds extra punch.
Thai rubies almost always lack the vibrancy of their Burmese brethren. They are cursed, Crowningshield continues, with the presence of iron, a trace element that affects color for the worse by adding purple and brown, all the while inhibiting fluorescence. Heating ruby is enough to alter the state of the iron and remove some of the purple and brown. But the process doesn’t significantly boost fluorescence. Hence heated Thai rubies still lack what one dealer calls “jazz.”
To a generation reared on Thai ruby, however, there is no way to appreciate this missing ingredient. Hard to define unless seen, it makes it even harder to justify the rather hefty price differentials between Burma and Thai rubies. Today, for instance, a very fine 3-carat unheated Burma ruby can easily command at least double the price of its Thai counterpart.
Thankfully, Burma/Thai price differentials narrow as stones get smaller. Very fine all-natural 1-carat Burma rubies currently wholesale for roughly 25% more than very fine 1-carat Thai stones. Considering the desperate disproportion between supplies of Thai and Burma stones, this makes Burmese goods a bargain.
Excerpts from “Consumers Guide to Colored Gemstones” by David Federman