ⅠaAB型天然钻石复合处理实验

Multi-process Treatments of Natural IaAB Diamonds

基于钻石在复合处理（辐照和高压高温处理）过程中的色心转变,在一定的处理工艺条件下,对25粒ⅠaAB型天然钻石进行复合处理,辐照处理后钻石呈浅蓝色、蓝绿色、绿色,复合处理后钻石呈金黄色和褐黄色。采用红外光谱仪,USB4000光纤光谱仪对复合处理前后的实验样品进行测试,发现复合处理前后钻石样品的红外光谱没有明显变化,钻石的类型没有改变,辐照处理后样品的紫外-可见吸收光谱在500~750nm的透光率减弱,750~800nm的透光率有所增加,辐照产生了741nm处的吸收凹谷,复合处理后,由辐照产生的辐照损伤心741nm消失,复合处理后钻石样品在500~800nm的透光率增加,表现在肉眼可以观察到钻石的亮度有所提高。

On the basis of the current situation and theory of diamond colour change domestic and overseas,natural type I diamonds were selected as object of the study.Experiments including irradiation and HPHT treatments were carried out on the 25 natural type IaAB diamond samples.The authors compared and analyzed the differences before and after treatment by using infrared spectrometer and UV-Vis spectrophotometer.In irradiation experiment,because of the different irradiation time,the samples received different irradiation dose,but all the samples changed into light blue,bluish green or green.After multi-process treatments including irradiation and HPHT,diamond samples turned into golden yellow.The infrared absorption spectra of diamonds before and after irradiation do not show much change.Some peaks may have a little change in intensity,but the type of diamonds does not change.UV-Vis spectra of samples after irradiation treatment show GR1 radiation damage at741 nm,and the transmittance among 550—750nm weakened,while the transmittance among 750—800nm enhanced.After HPHT,the peak of UV-Vis spectra at 741 nm disappeared,and the transmittance during 500—800nm increased,and as a result the treated diamonds appear brighter than untreated ones.