Natural Blue Sapphires E(IM1)
Results LA-ICP-MS

The study of the blue sapphires enhanced with the new method shows that color zoning in the gemstones is not related to the presence of Beryllium. The color zoning is produced in this sample from a pre-existing whitish band containing Titanium. A migration of Titanium, seen as a blue halo around the white band, occurred. The migration of titanium is restricted to about 200 micrometers, and well supported by chemical data. Due to a pre-existing in homogeneous chemical composition in the gemstone, heat-enhancement produced a complicated color zoning pattern with orangy-pink and blue oscillations (Fig. 57). The chemical zoning regarding Fe and Cr is following the faceted surface of the gemstone, with depletion in the rim and enrichments towards the center. Interference with the titanium zoning, at positions of both titanium and Fe-enrichments, has produced a blue color. “Padparadscha” colors were produced at Fe greater than 800ppm, Cr greater than 200-300ppm, Titanium lower than 200ppm, and Magnesium greater than 80ppm, while blue colors were produced at Fe greater than 800ppm and Ti greater than 200ppm. This is in strong agreement with the results from the study of the orangy-pink sapphires (See Fig. 49 and Fig. 53). All the trace elements found in these samples which are responsible for the color can be found in the natural unheated colored sapphires (Fig. 23, Fig. 64 and Table 5 and Appendix page 46 and 47). The zones of Beryllium in this sample were found to be concentrated in the outer areas containing unstable color centers producing a yellow to orange color (Fig. 4).