Transparent colored gemstones are loved for their beautiful colors. How they absorbed the visible light that passes through them determines their color. The study of light absorption by materials is called spectroscopy. Because the rainbow array of color was observed in gem materials is directly related to their chemical composition, spectroscopy is an incredibly effective to method for investigating the chemistry of gems.
Basle Anderson and James Payne formally introduced spectroscopy to gemology through a series of 40 articles published in the gemologist between 1954 and 1957. The use of spectroscopy and gemology actually predates these articles, as Anderson was teaching the technique in gemology classes as early as 1933. In his classroom the spectroscope and spectroscopy joined the microscope and refractometer as the third key tool of gemology.
The spectroscope quickly became an excellent tool for gemstone identification. Identifying stones with it is simply a matter of learning to recognize the light/dark colored patterns seen through it. The spectroscope has some limitations in the laboratory. With wavelength calibration added to the image of the spectrum, the spectroscope is capable of reasonably accurate measurement of spectral line. However, what it cannot easily measure is the strength of an absorption line or band.
At Suncoast Gems we have three different spectroscopes in our gemological laboratory to help us in the positive identification of gemstones and imitations that are very similar in appearance. If you would like we would be happy to give you a demonstration of how they work the next time you are in. Our mission is to offer the best gemological services in our area.