d.) More than 50 synthetic corundum samples and 15 irradiated synthetic samples were available for comparison.
e.) Commercially representative products of this new treatment included faceted natural orangy-pink and orange and yellow sapphires (origin Madagascar). They were obtained from three different companies: In November 2001 from KV Gems Co. LTD (Thailand), and in December 2001 from 2 other companies in Bangkok. This study also includes samples of African origin (Tanzania), samples obtained in February 2002, and 12 faceted orange-red to vivid orangy-red sapphires, produced by the new treatment in Chantaburi in December 2001.
f.) Further samples of this new treatment were selected from a large lot of sapphires - investigated in Chantaburi on 14th December 2001 - which were heated with the new method, but not repolished. This lot arrived directly at the heat treatment laboratory in Chantaburi after treatment (Fig. 2 and 3). The samples for this report were color sorted, then master sets of different colors were made, including white, blue, yellow, orange and orange-pink ("Padparadscha") colors produced by the new method. Outside of the dominantly produced typical orange colors in this lot, 12 white and four natural blue sapphires were also sorted. Some of this lot's sapphires were clustered together (due to the melting of non-sapphire materials in the treatment process (Fig. 3)). Three of these clusters were selected for this study from the same lots. Three "Padparadscha" samples from these lots have been re-cut, with 10%, 20% and 50% weight loss respectively.
g.) Typical samples suitable for the new heat treatment include faceted natural purplish-pink sapphires (heart and triangular shape) between 0.3 to 1ct, which were studied in November 2001 and subsequently heat-treated with the new method in commercial runs together with other dealers' samples in Chantaburi (the heat treating laboratory was not aware of GRS making test runs). 15 pieces from this lot were treated in Chantaburi between November and December 2001. The samples were studied before and after treatment.
h.) 15 natural pink sapphire pieces, as well as unheated violet, purple and "padparadscha" sapphires, were treated at a factory in Bangkok in February 2002 through a Thai Gems Jewelry and Trade Association (TGJTA) initiative (Further details see Table 6). The heat treating laboratory was aware of GRS making tests. Although the material was studied before and after treatment and the heat treatment tests used to support this study, treatment details were not disclosed and the treatment laboratory not shown.