Traditionally, the physical characteristics or phenomena for differentiating gemstones include : colour, gloss, transparency, hardness, cleavage, density, thermal conductivity, refractivity, birefractivity, reflectivity, spectral selective absorption, chromatic dispersion, pleochroism, polarised light, fluorescence, phosphorescence, and special optical effects, etc. Instead, the nondestructive methods play predominant roles. Due to the preciousness and the unique character, destructive methods are usually not applied to identifying the gems. Undoubtedly, it is important for museums or private collectors to evaluate the authenticity before reserving the objects. Some gems are either rarely found or of amazing scale so that the museums conserve them as priceless collections. Gems are always of special meaning on both human’s material life and spiritual world.
JADE 9 XRD SOFTWARE PORTABLE
Wider recognition and application of the portable XRF–XRD system in cultural heritage and gemological fields call for hardware development, software updating and more real application cases. The results indicate that the portable XRF–XRD system can be applied to identifying particular gemstones effectively, while single-crystal gems may not be identified very well.
Advantages, disadvantages and applicable range of the system were analysed. Normal XRD experiments were conducted in order to verify the results. The phase analysis process of each sample was described in detail and the most likely phases were determined. The XRF spectrum of each sample was analysed first to acquire the elemental composition qualitatively, and the information was then applied to refining possible phases. The key experimental parameters were optimized in order to obtain XRD patterns acceptable for phase identification in a limited time. The XRF and the XRD measurements for each sample were performed simultaneously. The samples were measured by groups based on the transparency and the complexity of molecular structure.
Nine gemstone samples were analysed by using a portable X-ray fluorescence–X-ray diffraction (XRF–XRD) system without any destructive preparation processes.
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