透闪石玉物相构成及沁蚀演化机理新解  

A new understanding of the phase composition and etching evolution mechanism of tremolite

作　　者：王云鹏 刘芳志 王传昌 马清林 WANG Yunpeng;LIU Fangzhi;WANG Chuanchang;MA Qinglin(Shandong Cultural Relic Conservation and Restoration Center,Jinan 250014,China;Joint International Research Laboratory for Environmental and Social Archaeology,Shandong University,Qingdao 266237,China)

机构地区：[1]山东省文物保护修复中心,山东济南250014 [2]山东大学环境与社会考古学国际合作联合实验室,山东青岛266237

出　　处：《文物保护与考古科学》2020年第6期1-12,共12页Sciences of Conservation and Archaeology

摘　　要：中国是世界上玉文化源远流长的地区,随着玉文化研究的深入和玉学的兴起,玉石的物相构成及受沁演化机理成为学界和出土古玉鉴定中的重要问题。由于埋藏环境的作用,许多玉器出土时的面貌和成分结构已发生很大改变。本研究运用扫描电子显微镜及能谱仪(SEM-EDX)、显微激光拉曼光谱仪(MLRM)和傅里叶变换红外光谱仪(FTIR)等分析设备,对湖北省京山市苏家垄遗址春秋时期M88号墓棺内出土的4件玉器残片以及1件现代透闪石玉原石开展比较研究。研究确认透闪石玉中除了纤维状的矿物成分,还包含玻璃相的高级脂肪酸盐,分布于晶界及晶体间隙的玻璃相脂肪酸盐在玉石晶链间形成缓冲,使透闪石玉具有较高的韧性,不易崩碎。当腐蚀发生时,脂肪酸盐会变质分解溶出,部分会在玉石裂隙及疏松处富集并吸附其他物质,致使玉石受沁。脂肪酸盐大量流失后,透闪石玉晶链因失去缓冲而极易碎裂。此时,链状结构中Ca-O键和Fe-O键因强度低于Mg-O键而优先断裂流失,使得玉石内阳起石结构减少,外观由半透明向不透明转变,甚至白化。关于古代玉石中脂肪酸盐来源及其对玉石影响的研究,为古玉研究开拓了新的途径。China is the most ancient area of jade culture in the world.With the rise of jadeology,the phase composition of jade and its mechanism of etching have become a concern to the community.In our study,we used scanning electron microscopy-energy dispersive X-ray spectrometry(SEM-EDX),laser Raman microspectrometry(LRS)and Fourier transform infrared spectrometry(FTIR)to analyze four jade fragments from Tomb M88 from the Sujialong Site in Jingshan,Hubei Province as well as one modern Hotan jade sample.In addition to the fibrous mineral components,tremolite jade also contains higher fatty acid salts which exist in a glass phase.The fatty acid salts are distributed as a buffer in the grain boundary and gaps,so that the tremolite has high flexibility and does not break easily.During the etching,fatty acid salts were dissolved out and some were enriched at cracks and loose areas,adsorbing other substances to cause jade to be etched.After the loss of a large amount of fatty acid salts,the internal chains of tremolite are prone to breaking.In this process,the Ca-O and Fe-O bonds in the chain are broken before breakage of the Mg-O bond due to their lower strengths.The actinolite structure is reduced accordingly and the translucent jade turns opaque and is even whitened.

关 键 词：玉器受沁 苏家垄遗址 芈克墓 玻璃相脂肪酸盐 SEM-EDX LRS FTIR 

分 类 号：K876.8[历史地理—考古学及博物馆学]