山东昌乐蓝宝石颜色与化学成分的关系

Study on the Relation between Colors and Chemical Compositions of Changle Sapphires in Shandong Province

产于玄武岩中的蓝宝石颜色通常较深 ,山东昌乐蓝宝石的颜色因其晶体巨大更显得深暗。这类蓝宝石曾多次进行过改色试验 ,但成效都不大。通过对电子探针及紫外—可见光—近红外吸收光谱图测试结果的分析 ,并对山东昌乐蓝宝石的颜色与化学成分之间的关系进行研究 ,结果表明 :昌乐蓝宝石的主要致色元素为Fe,Ti,Cr,Ni等 ,Fe2 O3+FeO含量高及TiO2含量少 ,以及成对Fe3+的大量存在是其颜色偏深的重要原因 ;TiO2 含量对蓝宝石颜色纯度影响很大 ,也是蓝宝石改色能否成功的重要因素之一。

The sapphire which occurred in basalt is generally with dark color. Due to huge crystal, Changle sapphires apperar to be darker. Many experiments on changing colors of Changle sapphires have been carried out, but the effect not obvious. By the analysis of results obtained from electron microprobe and ultravalet-visible spectrum-near infrared absorption spectrum sketch, and the relation study between colors and chemical compositions, some recongnizations have been got as following:major color-causing elements of Changle sapphires are Fe, Ti, Ni and Cr; the high contents of Fe 2O 3+FeO, low TiO 2 and abundant Fe 3+ are the major factors which make the sapphire color; and the content of TiO 2 effectes the color pureness of sapphire greatly, and it is also one of the important factors whether the sapphire′s color can be successfully changed or not.