On the basis of lab researches performed in 2009 for the gemmological properties and compositions of peripheral materials of the red of Tibet,the investigation team of National Gemstone Testing Center,China(NGTC) performed a field investigation on occurrence of international disputing about red of Tibet from the geology,mineral deposit,stratigraphy and geomorphology at the border area between Bailang county and Jiangzi county in Shigatse,Tibet(E29°04′01.5″,N89°20′54.8″) in May,2010.The investigation team interviewed the villagers of Mencuo and Zhalin villages,viewed the trade process and collected the red feldspar samples.The results show that the majority of red feldspar samples in the field were artificially placed on the ground surface and in the loose ground,which supports the previous deduction of lab researches in 2009.

Since 2008,whether the "red feldspar from Tibet" exists and whether such a stone is diffusedly-treated have been hot-debated issues in the gemmology communities at home and abroad.The gemmological characteristics of the surrounding rocks and the surface residues of the "red feldspar from Tibet" are studied presently by using the polarizing microscope,electron microprobe and X-ray photoelectron spectroscopy techniques.The results show that the original host rocks of the "red feldspar from Tibet" are composed mainly of intermediate-basic intrusive rocks containing glasses and bubbles,and that the surface residues of the red feldspar and its surrounding rocks contain plenty of copper and iron.Furthermore,the surrounding rocks and surface residues may have artificially been sintered at a high temperature in their later development stage.In this sintering process,part of dark minerals and some foreign substances such as co-solvents turned into glasses and bubbles.Further tests reveal that the majority of the "red feldspar from Tibet" samples under investigation might have been copper-diffusedly-treated.

Diamond laser marking is the mainstream diamond marking technology. The diamond laser marking system developed by the authors is constituted by pulsed laser, laser output lens and controller, CCD camera, special control software, IC digital card and computer, which can rapidly and clearly mark diamond without any damage to the quality of diamond. The system can be used for diamond sales and appraisal. The principle and application of the system are introduced in the paper.

The superficial characteristics of iridium-doped gold jewelry and the occurrence and the chemical compositions of doped material in gold jewelry have been investigated by using optical microscopy and X-ray fluorescence spectrum analysis.The results show that the doped materials are iridium,ruthenium,osmium,etc,which occur in independent phase.The proportion of(w(Ir+Os))∶(w)(Ru) is 65%~70%∶30%~35%.The densities of the doped materials are consistent with that of gold.The doping materials in gold jewelry result in the insufficient purity.The testing metheds of iridium-doped jewelry are probed.

珠宝检测机构必须重视客户服务及合同评审工作,改善服务水平和服务能力,以实现自身的发展。

国家珠宝玉石质量监督检验中心深圳实验室在2005年的检测工作中发现了掺入大量的铱、钌、锇等重金属的黄金饰品与处理、合成钻石,值得技监部门和质检机构重视.出于维护珠宝首饰市场的良好秩序、保护合法经营的企业和消费者利益的目的,现将对它们的鉴别方法介绍给读者.