Sapphires from Myanmar
Although Myanmar, once known as Burma, is a well-known source of some of the world’s best rubies, few are aware that it also produces fine sapphires. Although yields fluctuate due to internal politics and policies, quality sapphires have always been exceedingly rare – accounting for only about 10% of the total corundum yield.
Myanmar’s sapphire production is centered in the Mogôk Valley, which is located about 400 miles north of Myanmar’s capital Yangon. For at least a millennium, this remote, inhospitable region has yielded great quantities of rubies and sapphires, which have been prized by Chinese emperors, Shan warlords, Burmese kings, and foreign collectors alike.
Sapphires are found in quantity in only a few localities in the region, but they can be enormous – cut gems of over 100 carats have been known. Colorless, purple, blue, violet, yellow, pink, and green, sapphires are mined in the area. Although stones frequently contain quantities of rutile silk, they are otherwise known for their high clarity. Color zoning is not as prevalent as it is in stones from other locations around the world. Star sapphires from Myanmar are known for having stars that are noticeably more clear and distinct than those from other sources.
The rubies and sapphires of Myanmar are found in igneous rocks that have undergone a combination of contact and regional metamorphism. Weathering carries the corundum down from mountains to settle on the bottom of streams and rivers where it is recovered from alluvial deposits.
Mining is a mix of mechanized and primitive techniques, and gems may be extracted from pits in alluvial fields, open trenches in hillsides, excavations of limestone caves, and tunnels in host rock.
Although the fortunes of the Mogôk mines have risen and fallen over the centuries as management has shifted between private, imperial, and governmental oversight, experts hope that the great “Valley of Gems” will yield many more sapphire treasures in the future.