After this, Burma lent its hand to the Chanthaburi gem scene, with a new source of ruby from Mong Hsu.  This new source, one of the largest deposits of ruby in recent history, produced Burmese ruby with one problem, most of the red crystals had a bluish core which would make the cut stones look purplish.  Once again, the Chanthaburi burners came to the rescue.  With a new technique to heat the blue core out of the stone, which would leave some silk in its place, the “new and improved” Mong Hsu rubies were a hit, quickly dominating the market.