和田玉热处理改色仿子料工艺的实验与探究  

Experiment and research on the process of heat treatment of nephrite to change color imitating material

作　　者：李鸿禧 邓夏 陈忻 倪艳华 胡月伴 曾楚然 LI Hongxi;DENG Xia;CHEN Xi;NI Yanhua;HU Yueban;ZENG Churan(Guangzhou college of South China University of Technology, Guangzhou 510800, China;National Gemstone Testing Center Ping Zhou Lab, Foshan 528251, China)

机构地区：[1]华南理工大学广州学院珠宝学院,广东广州510800 [2]国家珠宝玉石质量监督检验中心平洲实验室,广东佛山528251

出　　处：《超硬材料工程》2021年第4期56-61,共6页Superhard Material Engineering

基　　金：华南理工大学广州学院校级重点学科建设项目CQ190046。

摘　　要：和田玉子料深受人们的喜爱,因其有限的资源和丰厚的利润,市场上出现的和田玉子料仿制品也越来越多。近来市场上出现一种带有红棕色皮色的和田玉,被称为“火烧红”,疑是由和田玉经过加热处理所形成。通过对天然的山料和田玉进行热处理改色实验,分别采用Fe和Mn试剂对样品进行热处理,均产生了黄-红褐色皮色。紫外-可见吸收光谱测试结果显示,Fe试剂处理的样品在327nm处会产生Fe3+的6A1→4T1跃迁所致的吸收;Mn试剂处理的样品在533nm处会产生Mn3+的5E→5A1跃迁所致的强吸收。X射线荧光光谱测试结果显示Mn试剂处理的样品表明Mn含量为1.43%~4.17%,而普通样品的含量仅为0.29%~0.39%,可作为无损检测的依据。热重及差热分析结果显示所有热处理的样品缺少在30℃~300℃范围内因吸附水脱水所产生的吸热谷;Mn试剂处理的样品在800℃~900℃出现β-褐锰矿分解所产生的强吸热谷。Nephrite has been developed in China for more than eight thousand years,and has been deeply be fond of due to its limited resources and huge profit.With more and more imitations of nephrite bloomed showing up on the market,among all the different types of nephrite,the most valuable is nephrite gravel.Recently,a kind of nephrite gravel with a reddish brown skin color,known as"fire red",appeared on the market,which is suspected to be formed by heat treatment.In this paper,through the experiment of heat treatment to change the color of nephrite and imitate nephrite gravel,the samples were heat-treated with Fe and Mn reagent respectively,resulting in yellow-reddish brown skin color producing on both.The results of UV-Vis absorption spectra showed that the absorption of Fe3+induced by 6A1→4T1 transition occurred in the sample treated with Fe reagent at 327nm.The strong absorption of Mn3+induced by the 5E→5A1 transition at 533nm was observed in the sample treated with Mn reagent.The results of X-ray fluorescence spectrum test showed that the Mn content of the sample treated with Mn reagent was 1.43%~4.17%,while the content of the ordinary sample was only 0.29%~0.39%,which could be used as a basis for nondestructive testing.The results of DTA analysis showed that all the heat-treated samples lacked the endothermic valley caused by water dehydration in the range of 30℃~300℃.The samples treated with Mn reagent showed strong endothermic valley caused byβ-braunite decomposition at 800℃~900℃.

关 键 词：皮色 和田玉子料 热处理 紫外-可见吸收光谱 差热分析 

分 类 号：TS933[轻工技术与工程]