Ever since Burma’s socialist government sealed off the country in 1962, Burma ruby has been an endangered species. But even before its borders closed, mining in the country’s principal gem tract at Mogok, in north central Burma, was in sharp decline.
One of the few American gem dealers alive today to have ever visited Mogok remembers that as of his last visit in 1960, miners were already reworking the tailings of combed over deposits, “The future of supply was open to question before Burma became off bounds,” he says.
This isn’t to say that mining has ceased. It is believed to continue but only in a token and largely clandestine manner. Most of what the West sees in the way of “new” Burma rubies, whether those mostly mediocre stones offered at once a year gem auctions in Rangoon or the modicum of far finer pieces smuggled into neighboring Thailand, are probably hoarded goods. The same goes for the majority of Burma rubies sold in major Asian gem centers such as India, Hong Kong and Singapore. In Europe and America, the market is almost entirely dependent on vintage goods, many from estates.
Given the profusion of heat-treated Burma pretenders, authentication of origin has become as important to gem dealers as authentication of authorship is to art dealers. The job of verifying Burmese origin is difficult, often involving intricate microscope scrutiny, as well as painstaking historical research. Few in the profession of gemology are trained for this work. And, indeed, the field of gemstone origin authentication is in its infancy, presently dominated by two labs, New York’s American Gemological Laboratory and Zurich’s Gubelin Laboratory, whose findings sometimes conflict.
Since an origin pedigree is now a prerequisite to sell Burma rubies in the auction and connoisseur markets, sellers will often submit stones to both labs and use the authentication certificate of whichever lab concludes the stone is from Burma. At present, the Gubelin Gemological Laboratory in Switzerland is the better known and preferred. But that doesn’t necessarily mean its work is better. To the contrary, American Gemological Laboratories has irked some dealers because it insists on noting whether or not stones, even those from Burma, are heat-treated—a reality for almost all modern-mined rubies. Many in the trade believe that this information should be excluded from origin reports, even though it is clearly required by Federal Trade Commission gem enhancement disclosure rules for the jewelry industry. In any case, indications of heat treatment on an origin certificate for a Burma ruby can prevent it from receiving as much per carat as a stone from the same place that the laboratory has validated as all natural. But heated or not, a fine Burma stone will be worth far more that its Thailand or Mozambique counterpart.
More on Thailand’s rubies next time…
Excerpts from “Consumers Guide to Colored Gemstones” by David Federman