山东昌乐蓝宝石的颜色成因与优化

THE MECHANISM OF COLORATION OF SAPPHIRE FROM CHANGLE,SHANDONG PROVINCE

本文对昌乐蓝宝石进行了大量的颜色指数测量。各样品的主波长虽多落在蓝紫—蓝—蓝绿区,但其纯度均很低,以致肉眼观察十分暗淡,近乎黑色。蓝宝石的颜色主要由全铁含量和Fe^(2+)/Fe^(3+)值决定。随Fe^(2+)含量的增多,蓝宝石的颜色由黄逐渐变为蓝紫色。热处理难以改变蓝宝石中全铁的含量,但可使不同价态铁的含量发生改变。昌乐蓝宝石中全铁含量太高,通常热处理效果不很理想。

Presented in this paper are the chromaticity indices of sapphire fromChangle. Most dominant wavelengths fall within the bluish violet-blue-bluishgreen ranges, but the saturation is very low, so the color is dull and dark. Thecolor of sapphire depends on total iron and Fe^(2+)/Fe^(2+) ratio. With increasingFe^(2+) content, the color will change gradually ftom yellow to bluish-violet. Theratio of Fe^(2+)/Fe^(2+) can be altered by heat treatment. However, the concentrationof isovalent iron remains unchanged. The thermal effect would not be strongin the case of high Fe content.