UV-Vis spectroscopy, one of the effective methods to study the chemical composition and crystal structure of gems, has been proved to possess extensive applications in Gemology. Compared to the traditional techniques of physical measurement such as refractive index and specific gravity, UV-Vis spectroscopy provides a more accurate, faster, simpler, less destructive means of identifying the gem's variety, whether it is natural or synthetic, and whether it has been treated. UV-Vis spectroscopy can also be used to study the mechanism and quantitative characterization of gem color, in some cases, to determine the origin of the gem.

1. Identify the variety of the gem

2. Identify the synthetic gem

3. Identify the treated gem

4. Study the mechanism of gem color

5. Quantitative characterization of gem color

6. Determine the origin of the gem

Figure 1. Tricolored tourmaline (left) and its non-polarized UV-Vis absorption spectra (right).