Energy-dispersive X-ray fluorescence(ED-XRF) is a qualitative, semi-quantitative, and probably quantitative chemical analyzer widely used for nondestructive analysis geology and gemology. Guild Gem Laboratories have applied this technique to identify species, synthetic methods, and treatments of gemstones, work out the color genesis and determine the geographic origin of some colored stones. In this article, some examples are given to illustrate the applications of ED-XRF to gemology.

1. Identify the species and subspecies of gemstones

2. Distinguish natural gemstones from synthetic ones

3.Detection of treatment

4. Color genesis research

5. Geographic origin determination

Figure 1. This plot shows that Fe content of Zambian emeralds is normally much higher than Colombian emeralds, which makes them easy to distinguish.