Than-tayar (Hundred Billions), Marble Ark, Mogok Township, Pyin-Oo-Lwin District, Mandalay Region, Myanmar

The area is situated at the bottom of a long, narrow ridge between 2 hills of the Kolan range. Rubies and spinels are recovered as detritus from numerous loos (twisted holes). Blue sapphires are often found in the soft alluvial floor of the caves.

Ref: Ted Themelis (2008) Gems and Mines of Mogok, p. 231

Gemstone List

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