紫色翡翠的矿物学特征初步研究

PRILIMINARY STUDY ON THE MINERALOGICAL CHARACTERS OF LAVENDER JADEITE JADE

通过对九个包括几种色调的紫色翡翠样品进行常规的标本描述、编光显微镜下薄片鉴定，结合红外光谱和X光衍射分析，轻系统地研究了紫色翡翠的矿物学特征，并根据能增分析结果，对紫色翡翠的致色机理作了初步探讨。结果表明：紫色翡翠的比重相对轻小；其主要矿物成分为硬玉，次要矿物为钟长石和透闪石，少量的霓辉石和霓石；硬玉可分为三个世代，紫色硬玉的晶形较好，多呈自形粒状交品结构，主要属于第二和第三世代，即形成时间相对较晚；紫色翡翠的颜色主要由致色元素Fe引起，同时，V，Ni，Mn等致色元素对形成紫色的不同色调也起一定的作用。

The mineralogical characters and colouring elements of lavender jadeite jade are summarized according to the studies under polarized microscope, infrared spectrum analysis, X-ray diffraction analysis and energy dispersive X-ray spectrum analysis of 9 samples which includes two samples of jadeite jade B. The results show that the specific gravities of most samples are less than 3. 33. The main mineral components are jadeite (>90% ), albite (3% ~8% ), tremolite (2% -5%) and a few aeginine-augite and aeginine. The jadeites in the samples can be divided into three epoches. Most of lavender jadeites with relatively good crystal forms belong to the second epoch and the third epoch. The lavender jadeite jade is coloured mainly by Fe, whereas some other colourins elements such as V, Ni, Mn are responsible for various tinges of lavender jadeite jade.