Yankin-taung (Safe Hill), Marble Ark, Mogok Township, Pyin-Oo-Lwin District, Mandalay Region, Myanmar
The single joint venture mine site is situated south of Kyatpyin-the-dot-sho.Rubies are recovered in primary marble (22°55'11"N. 96°26'01"E. at the worksite). Rubies, fewer blue sapphires and other gems are found in the alluvium (22°55'13"N. 96°26'04"E. at the worksite). No mining operations took place in 1999, but in 2001 the mines reopened to mine rubies, spinels, diopsides and scapolites. By November 2003 the gem mining activity was intensified.
Ref: Ted Themelis (2008) Gems and Mines of Mogok, p. 239