The Gemological Characteristic And Disscusion Of The Golden Seawater Pearl’s Exploitation From China

In this paper, golden seawater pearls were systematic studied by means of various modern testing methods, which results show the gemological characteristic of golden seawater pearls from China, especially in composition, mineral phase and configuration.The results as follows:1. The chemical compositions of the golden seawater pearls from China is mainly calcium carbonate, supplemented by organic substance and adsorptive water. In addition, there are many sorts of trace element in the pearls. The hydrolysis of organic substance which present in the pearls into17sorts of amino acids but without tryptophan.2. Aragonite and calcite present in the golden seawater pearls from China, which was studied by XRD, but no vaterite was found. The results of XRD is in conformity with the characteristic peak of standard aragonite, while the characteristic peak of calcite was found at d=3.0433,which occur as a weak peak. This shows that the mineral phase of the golden seawater pearls is mainly aragonite, supplemented by calcite.3. There are some absorption peaks,1797.61,1472.24,1082.99,861.36, 712.21,697.15cm"1in the FTIR spectrum, which is in conformity with standard aragonite,1783,1485,1082,859,712,699cm"1. That suggests absorption band and characteristic wave are identical with standard aragonite. The conclusion shows that the mineral phase of the golden seawater pearls is mainly aragonite, which proves the results of XRD.4. A series of sharp Raman peaks have been found at wave numbers,1085,705,275,208,192and154cm-1in the Raman spectrum, which caused by the vibration of CO32-. The characteristic of intensity and height about these Raman peaks are identical with aragonite, which show that the form of calcium carbonate in the pearls is aragonite.5.The compositions of the golden seawater pearls from China is mainly calcium carbonate, supplemented by organic substance and adsorptive water, which had been found by studying of DTA.6. The golden seawater pearl from China is made up with nacre and nucleus that is wrapped by nacre, which had been found by observing cross section of pearl with Optical microscope and SEM. Nacre, whose thickness is about0.4mm with close as a concentric circles consists mainly aragonite. Texture on the surface of golden seawater pearl from China is clos like the shape of terrce by SEM. Between the aragonite, there are a few of organic substance and prismatic layer may be found in some golden seawater pearls from China.