A handheld spectroscope for visible light shows the absorption lines of the elements involved in producing its color. For instance, it helps to separate ruby against red or pink sapphire . Spectroscope breaks up the light that is being transmitted from a gemstone to its spectral colors. The process allows the gemologist to see the various wavelengths absorbed by the gemstone. Thereby allowing the gemologist to know what elements are contained in the gemstone that are causing the absorption. Making this as one of the most important tools in identifying gemstones.
Spectroscopes allows you to analyze a loose or mounted stone's spectrum. They help distinguish naturally colored diamonds from those that have been irradiated and help to distinguish natural stones from synthetics by the stone's selective absorption of certain wavelengths