Sin-thé-gyant, Marble Ark, Mogok Township, Pyin-Oo-Lwin District, Mandalay Region, Myanmar

The area is a sinkhole characterized by karst topography, situated just east of Pyaung-pyin village. The rocks are graphite-phlogopite marble and others. The ruby-bearing marble bands are oriented along ~55°/130° and ~35°/115° directions. The texture of these marble bands is fine to medium grained, gray, light blue, whitish blue and brownish color, 15 to 140 cm thick.

Worksites No.1 and No.2: the gems were recovered from lebin and kobin mining operations, often reaching 30 meters in depth. The ruby-bearing marble mixed with byôn found in these lebins was brought to the surface and then broken to recover rubies. Also near-colorless, yellowish, yellow sapphires, diopsides and scapolites were found here.

Ref: Ted Themelis (2008) Gems and Mines of Mogok, p. 234

Gemstone List

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