What is diffusion treatment of sapphires?
• The person treating the stone starts with a colorless inexpensive sapphire. • A thin colored skin is grown over top of the stone giving the stone the look of a top quality colored sapphire. • High heat is used during this process and it can also create stress fractures. How do you identify diffusion treated sapphires? • When viewed under magnification diffusion treated sapphires will have darker color at facete junctions, and also in any fissures. • The girdle of the stone will also appear darker than the facet plains. • The colored skin is only about 1/10th of a millimeter deep so a scratch or gouge will remove parts of the treatment. • Mwthylene iodide will make the color differences very aparent.
