缅甸翡翠加热处理的特征研究

A Study on Jadeite from Myanmar by Heating

为研究缅甸翡翠中的哪些部位适合做烧红处理以及该部位能被烧红的原因,采用加热实验、偏光显微镜、红外光谱及差热分析方法对缅甸翡翠样品的原生部位、雾部位的加热前、后的特征进行了测试与分析。结果显示,翡翠中的蓝雾部位及黄雾部位适合做烧红处理,原生部位不适合烧红处理,蓝雾部位可以被烧成黄色及红色,黄雾部位可以被烧成红色。雾部位适合用来做烧红处理的原因在于,在低温的加热条件下,蓝雾部位中的大量的Fe2+发生价态变化,实现由绿泥石向针铁矿的转变所导致,该过程由表及里逐步进行。原生部位的主要矿物硬玉需被加热更高的温度,在破坏其晶格的情况下,才可以呈现出红色,且该红色不具有褐色调。

In order to study which part of jadeite from Myanmar can be used to do a red-hot processing and explain why it can be used to do a red-hot processing,this paper investigates the characteristics of heating of jadeite from Myanmar by using the thermogravimetric and thermal analysis（TG-DSC）,polarizing microscope and infrared spectrum（IR）.The results show that the origin zone of this type of jadeite cannot be turned red at a low temperature 400℃,while its fog zone can be turned red at this low temperature.In this process,the blue fog can be heated to yellow and red,and the yellow fog can be heated to red.The reason of this transformation is that a great amount of Fe2 ＋ in chlorite is oxidized to form into Fe3 ＋ at a low temperature,making the blue fog zone turn to yellow,while Fe2 ＋ in jadeite is so less and needs to be heated a more higher temperature that can make it be oxidized to Fe3 ＋,which will damage the lattice of jadeite.