In the 1950’s with the closure of the Mogok mines by the Burmese government, Chanthaburi’s stature grew even greater as massive supply shortages developed.  The mines within Thailand and around the city of Chanthaburi quickly stepped up to meet market demand, with control over a large portion of production and increasingly developed heat treatment techniques, Chanthaburi increased its standing in the international gem industry

In the late 1960’s, Chanthaburi began to look outward for sources of gemstones.  The first major source on which Chanthaburi set its sights were the Sapphire mines of Australia.  Australian blue sapphires are darker in color than their Asian counterparts; however, due to new heat treatment techniques developed in the furnaces of the burners in Chanthaburi, who were able to “burn out” the rutile silk in the stones, the Thais were able to produce an attractive blue sapphire.&