UV- VISIBLE ABSORPTION SPECTROMETE

Electronic absorption spectroscopy are widely used for quantitative determination of large number of inorganic and biological species.

In Gemology the absorption lines observed through the direct vision of hand held spectroscope for the visible range from 700 to 400 nm. While the advance instruments can measure between the range of wavelengths includes the two ultraviolet ranges (SWUV of 200 – 300 nm, and LWUV of 300-400 nm) and the very – near infra – red (700-900nm) as well as the visible region, thus displaying additional features, that may not be detectable with the hand held spectroscope , but may be useful for more advanced characterization.

Following are some of the board applications of UV –Visible absorption spectra in gem identification.

• IDENTIFICATION OF ORIGIN OF EMERALDS , RUBIES AND SAPPHIRE
• IDENTIFICATION OF IRRADIATION IN DIAMOND & YELLOW SAPPHIRE
• IDENTIFICATION OF SYNTHETIC YELLOW SAPPHIRES