RUBY MINES OF MOGOK
Hailing from Burma, now known as Myanmar, Burmese rubies are among the finest gemstones of their kind, as well as the most rare.
The Mogok Valley region of Myanmar was at one point the world's largest source of rubies, though the Mong Hsu area to the east, closer to the border of the Yunnan province of China, overtook the region in the early 1990s. While rubies occur naturally in other parts of the word-including nearby Thailand and Cambodia, as well as Mozambique and Tanzania-what sets Burmese rubies apart is their blood-red color.
Burma rubies are prized for their vivid, pure red color, though perhaps the most important factor in determining the stone's value is evidence of heat treatment (specifically, the lack thereof). Heat treating a ruby enhances the gemstone's color, by eliminating traces of blue.
This practice is not uncommon, though it has all but ensured that natural rubies-those without heat treatment-are both highly sought after and command higher prices in the market.