This map of Mong Hsu region in
northeastern Myanmar shows the areas of current mining activity. The alluvial deposits
(stippled areas), where the first rubies were found, are in river terraces southeast of
the town of Mong Hsu. Primary occurrences of ruby with adjacent secondary deposits were
discovered around Loi Hsan Tao. The pink region represents the area of gem potential
suggested by prospecting in 1993.
Mining of the secondary deposits is by the classic methods used in
Mogok and elsewhere in Southeast Asia. In and along the waterways, the gravels are removed
and washed in simple baskets.
Ruby deposits in the Mong Hsu region showing mining activities in the
secondary deposits. The picture shows the separation of the larger crystals of tremolite
by seiving before the rubies are washed from soil.
Mining of the secondary deposits is by the classic methods used in
Mogok and elsewhere in Southeast Asia. In and along the waterways, the gravels are removed
and washed in simple baskets. 
