jade, jadeite, fei cui, zircon, inclusions, gems

As the practice of bleaching and impregnating jadeite has become more common over the last few years, the amount of jadeite we test in the laboratory has increased signifi-cantly. During the microscopic exam-ination of one variegated green jadeite cabochon for possible evidence of treatment, we noted that the stone contained a number of small crystal inclusions, some of which reached the surface (figure 4). These surface-reaching crystals appeared to be somewhat harder than the surround-ing jadeite, and in reflected light they had a higher surface luster. With the recent acquisition of GIA’s Renishaw Raman Imaging Microscope System, we were able to examine two of these crystals nondestructively. By focusing the argon laser through the 50 x objective of the Leica targeting microscope and run-ning several continuous scans, we obtained clear spectra of the two “inclusions.” A computer search of our data base revealed that these spec-tra matched the spectrum for zircon. Visible characteristics of the inclu-sions (e.g., crystal form, color, trans-parency, and relative hardness) were consistent with this identification. This is the first time that we have encountered zircon crystals as inclu-sions in jadeite. Coincidentally, about a month prior to our discovery, a zir-con inclusion in a jadeite cabochon was also identified by means of the same technique at the Center for Gemstone Testing in Bangkok (Ken-neth Scarratt, pers. comm.).