'Tanusorn'-type Blue Sapphire Treatment

Thailand is perceived as one of the important gemstone refineries of the world + and now comes a new type of blue sapphire treatment, 'Tanusorn' type blue sapphires: 'Tanusorn' is named after Tanusorn Lethaisong, the gem 'chef', where semi-translucent pale colored sapphires consisting of many cracks are exposed to high temperature heating technique (s) involving cobalt and lead containing flux + the resultant blue coloration is due to the inclusions of blue cobalt-bearing solid residues left along healed fractures + if in doubt always consult a reputed gem testing laboratory.