The
center of Ruby gemstone trade is in Bangkok, Thailand. The Chantaburi
Province in Thailand has always been an important source of Rubies,
producing gems with excellent clarity but with less desirable browner
tones. However, the color of Thai Rubies are able to be improved by
heat treatment. The Thai Ruby deposits were exhausted in the 1980's.
The
most valuable Rubies with the finest natural color come from Mogok,
Burma (Myanmar). There are strict trade embargoes and restrictions again
Burma for its human rights violations, and several countries,
especially the United States, ban any exports from this county. The Ruby
mines of Mogok have been under the tight control of the Junta
government; however, a new very significant Ruby source was discovered
in Burma in 1992 in Mong Hsu. The color of these Rubies aren't as good
as Mogok, but they too can be improved through
heat treatment.
In
2000, new Ruby sources were discovered in Madagascar (in Vatomandry and
Andilamena). These deposits turned out to be very extensive and
productive, and Madagascar is now one of the leaders in Ruby output.
Other important Ruby sources include Sri Lanka, India, Cambodia,
Vietnam, Tanzania, and Mozambique. Other sources of Ruby include
Afghanistan, Pakistan, Tajikstan, Australia, and the U.S. (North
Carolina). - See more at:
http://www.minerals.net/gemstone/ruby_gemstone.aspx#sthash.FXK6cPMw.dpuf