The mining area of Htan-saing is situated west of Bernardmyo village. Most of the gems found are spinels. Some low-to-medium quality blue sapphires and fewer rubies are also found in the alluvium with schorl. For many years the area at Htan-saing was working seasonally using lebin
-dwin and myaw-dwin
mining methods. In 2005 the gem mines at Htan-saing were depleted.
Ref: Ted Themelis (2008) Gems & mines of Mogok, p. 181