This mining area was known before the 1970s. It is situated about 8 km from Mogok town, between Dattaw in the north-east and Pein-pyit village in the south-west. It is close to Mogok-Momeik road, forming a natural basin where many gems have accumulated. Another mining area is situated at the base of a marble faulted scarp in contact with garnet-bearing gneiss; leucogranite rocks and several skarns are also known in the same area. For many years gems have been mined in the loos (loo-dwin
) situated in the adjacent hill.
In 2001 these mines produced mostly spinels
(60%), near-colorless, greenish-blue, purple and other colored sapphires
(5%), other gemstones (25%). In 2004, most gems mined were blue or blue/green sapphires, fewer of fine quality; also some rubies. Other gems found iclude quartz
, near-colorless to yellowish and greenish chrysoberyl
. Vivid green grossular
suitable for cutting brilliant gems below 2 carats were also recovered.
Most of the gems are found in sandy byôn
using open-pit mining methods. Blue and blue-green sapphires, some milky-silky are also found in the alluvium and they are similar to those found at Pyant-gyi
. Some of these sapphires are suitable for heat-treatment to enchance their color and increase their transparency. Rubies
are found in the adjacent primary marble deposits.
Ref: Ted Themelis (2008) Gems and Mines of Mogok, p. 192