Mong Hsu Ruby Mines.
The Mong Hsu Ruby Stone tract was officially opened in July 1992 in the area near the Salween or Thanlwin River at the border region to Thailand about 180 km east of Mandalay by a government statement.
Until this time Mong Hsu was only a secondary village but after the declaration the town got very busy because it was known since decades that rubies are plenty there and more than 500 companies moved in.
They are engaged in ruby and sapphire mining on around 1,600 properties with official concessions. More than five million carats were extracted and sold by 2002 which were flooding the ruby market and reducing the price of rubies for smaller stones per carat of around 20%.
Local people were allowed to lease several 200 square feet of land for 3 years through tenders and this has been at a fixed price and immediately released to others at higher prices in particular plots of land with a reputation for quality gemstones are highly prized for the higher cost
this rental and sub rental chain. Many ruby mine rights were sold to local proxy who function as front for Thai dealers. They all are very experienced in the corruption infested business with Thai dealers.
Particularly interesting is the Loi Saung Htauk hill area.
Particularly interesting is the Loi Saung Htauk hill which consists of ruby grown on upper Paleozoic marble. Caves and holes are dug into the hill to preserve these marbles, after the marble is broken to extract rubies this mining area has the most valuable Burmese rubies of the area. Miners carve tunnels deep into the hill and sometimes at a depth of more than 100 meters.
Gems are also found in the limestone caves since they fall of marbles due to the erosion of underground streams where the stones are buried in the sand. An open pit system is also practiced where sand and gravel are absorbed and sorted by a gravity separation system. Since the stones have a high magnesium content the gems have a bluish hue.
These raw ruby stones are not very attractive at first.
These ruby stones are not very interesting at first but when they are heat treated in special ovens they turn into beautiful red stones. Most of the gemstones are sold as rough stones mainly to gem merchants in Thailand who perform the heat treatment in Chanthaburi. In fact, almost all good rubies up to about 3 carats from Myanmar are heat treated.