RESUMEN
Weathering & transporting and depositing processes may improve the quality of some natural low-quality jadeite through reaction with surrounding water fluids. But the mechanism of such water-rock reaction has not been known clearly to date. Applying microscopic Fourier transform infrared spectroscopy (Micro-FTIR), this paper carried out comparatively in-situ research of jadeites' mineral composition before and after water-rock reaction. The results show that water-rock reaction cannot impact jadeites in their major and minor element composition, but greatly change their water content. Jadeites became richer, with even several times increase, in water content, after experiencing water-rock reaction, and hence show a shift of absorption peak at 3 550 cm(-1) to higher frequency. The mineral crystals of these jadeites showed reglar variation in water content from core to edge, and these jadeites have more water in marginal area than in center area, being opposite to the change in water content in jadeite during high temperature and pressure metamorphic process, hence implying that there are different mechanism and shift direction for H+/OH of jadeite between high pressure metamorphic process and low temperature water-rock reaction. We think that this finding may contribute to understanding the behavior of water in jadeite during metamorphic process and the mechanism of jadeite quality improvement.
RESUMEN
The geographic locality determination of diamonds is of great significance in understanding the mantle evolution, restricting the illegal trade of conflict diamonds, etc. In the present article, the in-situ analysis of micro-FTIR surface scan technique was first applied to analyze 14 IaAB natural diamond specimens from China's three commercial localities. According to the FTIR spectra of diamonds, the nitrogen contents were calculated (1616 data points of FTIR) and used for mapping tracer. Th results showed that the nitrogen contents and its aggregation often varied in the process of diamond growth, and the nitrogen contents in initial nucleation stage could be higher or lower than in other stages. It is not an unidirectional variation for nitroge contents in different growth stages, indicating that the carbon and nitrogen had a complex exchange with mantle fluid during the diamond's crystallization course. It was regionally different between the diamonds from the three localities in the frequency distribution of nitrogen contents and NB%/N(T). Micro-FTIR mapping is more intuitive than the method of selecting discontinuous points, and it can trace the heterogeneous growth of nitrogen impurities in natural diamonds consecutively.
RESUMEN
Xiuyan, Liaoning was an important locality of jade material of the Red Mountain Culture in the Neolithic Age in Chinese history where there are two types of raw material of nephrite jades, namely gravel nephrite jade (Hemo Yu in Chinese) and old nephrite jade (Lao Yu in Chinese). In the present paper, Laser Raman spectrum technique was applied to analyze the graphite enclaves in the nephrite jades of the two types of materials. The results show that the graphite enclaves in the two types of jades have different characteristics of Raman spectra, indicating that they probably were formed under different geological conditions, or originated from different ore-forming periods or were exploited from different section of ore body. Hence, laser Raman spectrum technique could be used as a supplementary measure for nondestructive detection to determine the occurrence of jades.
RESUMEN
The object of the present study is the synthetic jadeite jade produced by American General Electric Corporation. Fourier transform infrared spectroscopy (FTIR) and Laser Raman spectroscopy were used to test its spectral properties in order to examine the feature of this kind of synthetic jadeite jade by vibrational spectroscopy and to figure out the mark for discriminate synthetic jadeite jade from natural jadeite jade. The study shows that GE synthetic jadeite jade is identical with natural jadeite jade in the main on fingerprint region in FTIR; There are clearly differences in the 2 000 -4 000 cm(-1) functional region in FTIR: a group of frequencies at 3 375, 3 471 and 3 614 cm(-1) indicate vibration absorption of O-H. GE synthetic jadeite jade has proven consistent with natural jadeite jade in the laser Raman spectra by a group of sharp scattering peaks at 376, 700, 989 and 1 039 cm(-1). In addition these scattering peaks show an intact crystal shape. The FTIR peaks and Raman spectral peaks shift to higher frequencies showing GE synthetic jadeite jade lacking isomorphism of heavy positive ions.
RESUMEN
The ancient tombs of Henglingshang site in boluo county are the most significant graveyard site of Shang-Zhou period in Guangdong province as yet. Based on a series of scientific studies on the jade samples from these tombs, the authors found that there are 2-3 characteristic peaks at 2,960 cm(-1) (quite poor), 2,920 and 2,853 cm(-1) in the infrared spectra. According to the tests and analyses of the infrared spectra of pure waxes and other modern jade wares treated with wax, the authors believe that these unearthed jade wares were enhanced with wax and the ancestors of Lingnan region in Shang-Zhou period (1600B.C.-221 B.C.) probably understood treating jade wares with wax to enhance their appearance.
