缅甸翡翠次生色的可见光吸收光谱的一阶导数谱研究

STUDY ON THE SECONDARY COLOUR OF MYANMAR JADE BY FIRST ORDER DERIVATIVE UV SPECTROPHOTOMETRY

缅甸翡翠颗粒中的充填物的谱学变化特征对于次生色的形成具有重要意义。本文采用可见光吸收光谱的一阶导数谱,对缅甸次生翡翠矿的次生色部位进行了研究。研究结果显示:翡翠的红黄雾主要是由蓝雾转变而来的,绿泥石在向赤铁矿转化的过程中,使得蓝雾区的颜色由灰绿色变成黄、红色。黄雾的致色矿物主要为针铁矿,红雾的致色矿物除了针铁矿还有少量的赤铁矿。与色彩相似的烧红翡翠比较,天然红翡(红雾)的可见光吸收光谱的一阶导数谱显示出明显的针铁矿特征,而烧红的则为赤铁矿。

The variation of first order derivative UV spectrophotometry of fillings in Myanmar jade plays a significant role in the formation of secondary color of Myanmar jade. In this paper, the secondary color of Myanmar jade has been studied by using first order derivative UV spectro-photometry. The results showed that red or yellow fog zone changes only from the blue fog zone. The change of red or yellow fog from blue fog is resulted from the transformation from chlorite into hematite. The fog zone of jade presents yellow color when it contains goethite,and it pres- ents bleeding red when containing very small quantity of hematite. Compared to the heated red jade with the same red coloration degree,the natural red jade shows mainly the wavelength of goe-thite,but the heated red jade show mainly the wavelength of hematite,which may be a basis for their identification.