摘要
对天然无色—浅黄色方柱石样品进行电子辐照改色处理,并对部分改色后为褐色/烟紫色的样品进行了热处理,肉眼观察颜色变化情况并进行紫外-可见吸收光谱测试。结果显示,电子辐照处理可使无色—浅黄色方柱石样品变为紫色、黄色,部分样品带棕褐色调。经电子辐照处理成紫色的方柱石的紫外-可见吸收光谱在黄绿区有宽的吸收带;辐照处理成黄色方柱石的紫外-可见吸收光谱中吸收峰位置与天然方柱石基本一致,蓝紫区的吸收明显增强。笔者推测电子辐照致方柱石产生紫色的原因与天然紫色方柱石颜色的成因可能相似,而产生黄色的原因可能与O-色心有关。加热处理实验结果表明:恒温时间为2h,恒温温度在500℃以下时,辐照产生的不理想的褐色调不能被有效消除;恒温温度为600℃,恒温时间2h以上时,辐照改色的样品褪色为近无色—浅黄色;加热气氛对方柱石颜色变化的影响不大。
Natural colurless-yellowish scapolite effected by electron beam irradiation and heat treatment were investigated. After electron irradiation, some scapolites turned into purple, and showed a wide absorption band in the green-yellow region. Some other samples turned into more saturated yellow after being irradiated, and the position of the absorption peaks in the UV-Vis absorption spectra were similar with natural scapolite, but with a higher absor-bance in purple-blue region. The UV-Vis spectra indicated that the purple colour of irradia-ted scapolite might have the same genesis as natural purple scapolite, whereas the yellow col-our of irraidated scapolite might cause by O- hole center. The results of heat treatment indi-cated that heating to 500℃ and holding for 2 hours in reducing atmosphere could not reduce the brown hue of irradiated scapolite, while subjected to 600℃ for 2 hours or 4 hours in re-ducing atmosphere could make the samples fade. The atmosphere of heat treatment does not produce big difference to the colour change.
出处
《宝石和宝石学杂志》
CAS
2017年第1期22-29,共8页
Journal of Gems & Gemmology
基金
中国地质大学(武汉)珠宝检测技术创新中心开放基金CIGTXM-2017001
文章编号CIGTWZ-2017001
