Synthetics and Simulants

identified the gem as glass, but the nature of the strange veins containing tiny trapped gas bubbles remained a mystery. Fourier-transform infrared (FTIR) spectroscopy was performed next, but no polymers were detected. The RI was recorded as 1.52, and we concluded that this gem consisted of a solid piece of green lead glass. Viewed with the microscope, an experienced eye might sense that there was something unusual about the ‘emerald’, but the veins of fine bubbles masked many of the properties that would normally indicate glass. The veins did not conform to a typical emerald fissure pattern, yet were not obviously ‘wrong’ in their appearance. Surface scratches and abrasions were more typical of glass than emerald. When observed with the Chelsea colour filter, the gem remained green despite having the general appearance of a Colombian emerald. Also, the broad table and low crown are not often seen with emerald, nor are they typical of imitation stones. The diamond mounting certainly added credibility to the centre stone. SYNTHETICS AND SIMULANTS