Feature Gems & Gemology, Summer 1982, Vol. 18, No. 2

Heat Treating Corundum: The Bangkok Operation

Following up on Nassau's 1981 article on the technical aspects of heat treating ruby and sapphire, the author reports his personal observations of the actual heat treatment process in Bangkok. He discusses the potential effects that this process can have on a stone - both positive and negative - and emphasizes the importance of the natural make-up of the stone itself to the success of heat treatment.