Pingu-taung-pyant (Plains of the Spider Hill) is an extension of the Inn-gaung gem mining area. The gem mining is situated to the north of the sites along the shallow banks of the Pingu-taung stream. About two-thirds of the gems recovered are rubies
, with the remainder consisting of blue and other colored sapphires
. Star rubies
and fewer star sapphires
are occasionally found. All the gems are recovered from the alluvium, by open-pit mechanized mining operations. In a nearby area leading to Baw-lon-gyi
rubies, spinels and occasionally blue sapphires are recovered, some of them weighing over 10 carats.
Ref: Ted Themelis (2008) Gems and Mines of Mogok, p. 245