摘要
热处理工艺可使绿柱石类宝石的色泽与透明度增强,从而提高宝石品质和价值。对新疆阿勒泰地区的海蓝宝石进行热处理实验,分析了热处理过程中温度、气氛、保温时间等因素对改善宝石颜色及透明度的影响,并对热处理前后的紫外—可见光谱特征进行了对比。结果表明,采用石墨为填料,加热温度450℃并保温3h,颜色由原黄绿色转变为海水蓝色,透明度也相应提高,改色效果理想和稳定。热处理及石墨的还原性,使矿物中含有的铁离子价态发生变化,是宝石颜色及光谱特性发生变化的关键。
Heat treatment can enhance the color and transparency of gem-class beryl to improve its quality and value. To test the effects of heat treatment on aquamarine of the Altay region, Xinjiang, we measured the influence of temperature, atmosphere, and holding time on improvements to color and clarity. These effects were quantified by comparing the characteristics of the UV-visible spectrum before and after heat treatment. The results show that the effects of color correction are enhanced and more stable when graphite is used as the filler material, temperature is 450℃, and holding time is 3 hours. This changes the gem color from the original yellow-green to sea blue, and improves transparency. The changes in color and transparency are controlled by the valence state of the iron ions and by reduction of graphite during heat treatment.
出处
《上海国土资源》
2012年第4期72-75,共4页
Shanghai Land & Resources
基金
国家自然科学基金项目(49772096)
关键词
绿柱石
海蓝宝石
热处理
改色机制
紫外-可见光谱
beryl
aquamarine
heat treatment
mechanism of changing color
UV-VIS spectrum
