|国家科技期刊平台
首页|期刊导航|岩石矿物学杂志|热处理对黝帘石颜色的影响及其致色成因探讨

热处理对黝帘石颜色的影响及其致色成因探讨OA北大核心CSTPCD

Study on the effect of heat treatment on the color of zoisite and the cause of coloration:The example of yellow and blue Tanzanian zoisite

中文摘要英文摘要

坦桑尼亚的天然蓝紫色黝帘石(也被称为坦桑石)产量稀少,储量较低.然而,通过热处理优化改色后,黝帘石的经济价值会得到显著提升.但多年来,关于热处理后黝帘石的蓝紫色成因一直存在争议.本文选取天然的坦桑尼亚黄色及蓝色黝帘石为研究对象,通过设置300℃、400℃和500℃3个不同的温度条件,并利用L*a*b*颜色参数对样品的颜色变化进行了量化分析.热处理前不同颜色黝帘石的宝石学特征具有一致性,热处理后结果表明,500℃左右的温度是浅蓝-蓝色黝帘石的最佳改色条件.经过热处理黝帘石的蓝紫色调明显增强,通过调整温度可有效调控样品中的黄色或褐色调.黄色黝帘石在热处理后展现出从黄褐色到蓝紫色的独特变色效应,而400~500℃是这一颜色变化的临界温度范围.结合EDXRF、LA-ICP-MS及UV-VIS等多种分析手段,认为天然黝帘石的蓝色主要由V3+和Ti3+导致,黄色则主要由Ti3+引起,V/Ti值在天然黝帘石的成因机制中起辅助作用.此外,热处理后黝帘石蓝紫色调的产生与增加以及黄色→蓝-蓝紫色的转变与Ti3++V4+→Ti4++V3+的电荷迁移密切相关.

The natural Tanzanian zoisite(tanzanite),with its distinctive blue-violet tone,is a rare and valuable gemstone.Heat treatment can optimise the color of zoisite and make it more economically valuable.However,the exact cause of this captivating blue-violet of zoisite has been a subject of debate for years.This study presents an examination of natural yellow and blue zoisites.The color changes of stones at different thermal stages were ob-served by setting three different temperature conditions 300℃,400℃ and 500℃,and using the L*a*b*color pa-rameter.The research findings indicate that the gemological properties of different colored zoisites remain consistent before heat treatment.It was determined that a temperature of approximately 500℃ is optimal for achieving a light blue-violet tone in zoisite.Heat treatment results in a pronounced enhancement of the blue-violet hues,enabling the modulation of zoisites'yellow or brown undertones through temperature control.Notably,the yellow zoisite expe-riences a fascinating color transformation from yellow-brown to blue-violet,with the critical temperature range between 400℃ and 500℃.Using energy dispersive X-Ray spectroscopy(EDXRF),laser ablation inductively coupled plas-ma mass spectrometry(LA-ICP-MS)and ultraviolet and visible spectrophotometry(UV-VIS)techniques,the study identified that the blue color in natural zoisite is primarily caused by V3+and Ti3+ions working in tandem.On the other hand,the yellow color is mainly attributed to Ti3+.The V/Ti ratio plays a supporting role in coloration of nat-ural zoisite.Moreover,the development and intensification of blue-violet tones in heat-treated zoisite,as well as the transition from yellow to blue-violet,are intricately linked to the charge migration of Ti3++V4+→Ti4++V3+.

杨淑淇;刘迎新

中国地质大学(北京)珠宝学院,北京 100083

地质学

坦桑尼亚黝帘石热处理颜色致色成因

Tanzanian zoisiteheat treatmentcolorthe cause of coloration

《岩石矿物学杂志》 2024 (003)

503-517 / 15

10.20086/j.cnki.yskw.2024.0302

评论