[Gemology characterization and identification of beryllium diffused, heated and untreated bicolor sapphires from...

Be-diffused, heated and untreated bicolor sapphires (blue and yellow) from Changle City, Shandong Province, China were studied by using standard gemological methods, ultraviolet-visible (UV-Vis) spectroscopy, infrared (IR) spectroscopy, electron microprobe, and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to obtain the spectra characterization, and to suggest identification methods for them. Only Fe(3+)-Fe3+ absorption bands formed in ultraviolet region appear in Be-diffused bicolor sapphire, which is especially strong at 377 nm. In IR absorption spectra, absorption peak at 3 310 cm(-1) appears in heated and untreated bicolor sapphires, while it disappears in Be-diffused bicolor sapphire. Therefore, UV-Vis and IR absorption spectra can be used to identify Be-diffused, heated and untreated bicolor sapphires. On the other hand, methylene iodide immersion observation also can be used to identify Be-diffused bicolor sapphire.