Pink gem spinel
and star sapphire
The area was known before the British annexation of Burma (1886). The current mining area is situated NE of the Mandalay-Mogok road, adjacent to the Karen village of Kabaing.
Granite microgranite is the principle rock. In 1999 SE of Kabaing village several joint venture mines were in operation , using mechanized open-pit and myaw-dwin
mining methods, producing blue sapphires
and some rubies
of all qualities.
One of the mines (U-Soe-Myint-Tun Private Mine) was in continuous operation since 1996, producing ruby, blue and fancy-colored sapphire, quartz
, six-rayed star rose-pink quartz, chalcedony
) and other gems. Of all corundum recovered about 20% were small size rubies of good quality; 80% were mostly blue sapphires of cabochon grade and fewer of faceting grade. Rubies and sapphires up to 10 ct were often found but they were opaque and excessively flawed. The largest blue sapphire found at Kabaing was 502-carat prismatic crystal.
Ref: Ted Themelis (2008) Gems and Mines of Mogok, p. 263