Gem Organic Filler Material Raman Spectroscopy Study

A gemstone is the naturally occurring crystalline form of a mineral, which is desirable for its beautiful colors and attractive lustre, also valuable in its rarity and durable enough to be enjoyed for generations. Since the beauty of gemstones origin from nature, they symbolize the wealth and authority; and the gemstones collection that represented the noble life is the convenient way for people to promot their society reputation, leading to the prosperous of jewelry market. However, the limited nature resources of good gemstones confine the further development of jewelry. Meanwhile, many gemstones have defects in part, so many method have been tr ied and used to correct these defects to improve the quality of gemstons.Gemstones are often treated to enhance the color or clarity of the stone,and many method of treatment have been used, such as heating, bleaching, waxing, oiling, coloring and fracture filling. Among these, fracture filling has been in use with different gemstones such as diamonds, emeralds and sapphires because the resulting gem is stable. Since many material such as wax, oil and plastic are used widely in fracture filling, such treatments are fairly diffictult to detect.The Raman scattering effect was discovered seventy years ago, which is a non-destructive analytical technique suitable for different materials. The signal of the Raman effect could be strong enough with less samples, and it could be used as a tool for analyzing the composition of liquids, gases, and solids. When light is scattered from an atom or molecule, most photons are elastically scattered, such that the scattered photons have the same frequency and wavelength as the incident photons. However, a small fraction of the scattered light, which is responsible for the Raman effect, is scattered by an excitation, with the scattered photons having a frequency different from that of the incident photons. Raman spectroscopy employs the Raman effect for materials analysis. The frequency of light scattered from a molecule may be changed based on the structural characteristics of the molecular bonds, which leads to some special peaks in the raman spectroscopy, being used for different materials analysis.Now, there are many portable Raman spectrometers have been promoted and used in many fields for their convenience, easy-to-use and good results. Especially, it is very easy to obtain some significant Raman spectroscopy for wax, plant oil and plastics, which have been wildely used as organic filling materials for g mstones.In this paper, the Raman spectroscopy of 10 gemstones with difffernt organic filling materials have been studied. It was found that the Raman spectroscop i es of these filling materials are different from those of the studied gemstones; and they could be rapidly detected by mapping their Raman spectroscopies with those of the gemstones together or by checking their feature peaks stored in the Raman-Database. The conclusion summarized from these results broaden the application of the Raman spectroscopy in the field of gemstones detection, and provid new method for detecting the fracture filling treatment used for gemstones.