晶化时间对高压高温合成翡翠品质的影响

Crystallization Time on Quality of Synthetic Jadeite under High Pressure and High Temperature

翡翠颜色艳丽,结构细腻,受到国人的追崇。近年来,由于天然原料的短缺,人工合成翡翠的研究逐渐受到关注。本文就高压高温下合成翡翠的时间对其品质影响进行探讨。实验采用溶胶-凝胶法制备合成原料,在1 100～1 500℃、4.0～6.0 GPa的高压高温条件下合成1～10 h,实现非晶态向硬玉晶体的转化。合成翡翠样品的基本宝石学特征、红外光谱及紫外-可见光谱与天然翡翠的基本一致。随着合成时间的延长,合成翡翠样品的透明度增加,由微透明向半透明转变;X射线粉末衍射分析表明,合成翡翠中的硬玉衍射峰高而窄,合成时间越长其结晶纯度越高;SEM及偏光显微镜观察结构特征表明,延长晶化时间有利于晶粒生长、结构致密,有利于获得优质合成翡翠。

Jadeite is well popular by its gorgeous colour and delicate structure. In recent years, due to the shortage of natural jadeite resource, the researches of synthetic jadeite have attracted more and more attention. In this paper, the authors discussed the effect of holding time of synthesis on the quality of jadeite under high pressure and high temperature. The synthetic raw materials were prepared by sol-gel method and they were transformed into jadeite crystal during 1 100-1 500 ℃ under 4.0-6.0 GPa for 1 to 10 hours. The basic gemmological characteristics, infrared spectra and ultraviolet-visible spectra of the synthetic jadeite samples are almost the same as those of natural jadeite. XRD analysis showed that the crystalline purity of jadeite was higher with the increase of synthesis time, and the longer the holding time period was, the sharper the diffraction peak was. SEM and microscopic observation showed that the longer the holding time period was, the better the crystal growth of jadeite, the more compact the structure of jadeite was, and the better the crystal quality of jadeite was.