摘要
重庆大足宝顶山释迦牟尼涅槃圣迹图(即卧佛)是世界文化遗产大足石刻群中最大的一尊造像,亦是世界最大的石雕半身卧佛像。在千百年自然营力和人为因素的影响下,大足卧佛表面出现了颜料脱落、霉变滋生等多种病害。为了实现“原材料、原工艺”的保护修复,需要对颜料成分进行分析鉴定。利用显微拉曼光谱(μ-Raman)等技术对佛像表面的颜料和打底材料进行了分析鉴定,同时探讨了其中白色颜料、绿色颜料的可能来源及颜料种类与霉变的关系。实验结果表明:卧佛表面每种彩绘颜料背面均以白色物质打底,打底材料的拉曼光谱在1006 cm^-1处存在强特征峰,与石膏峰位及强度匹配度极高,且杂质峰少,鉴定打底材料是较高纯度的石膏(CaSO 4·2H 2O)。表面装饰有红、蓝、白、绿等彩绘颜料,其中红色颜料为常见颜料土红(Fe 2O 3),其性质稳定,广泛使用在壁画、彩绘陶器等各类彩绘文物中;结合偏光显微分析鉴定出蓝色颜料为人工合成颜料群青(Na 6-10 Al 6Si 6O 24 S 2-4),其颗粒均匀、粒度一般<5μm;白色为常用颜料碳酸铅式铅白(PbCO 3)和罕见颜料砷铅矿(Pb 5(AsO 4)3Cl)的混合物,砷铅矿作为颜料在大足石刻属首次发现;绿色颜料在859 cm-1处出现最强特征峰,是AsO-4伸缩振动产生的,鉴定绿色颜料为少见的氯砷钠铜石(NaCaCu 5(AsO 4)4Cl·5H 2O)。大足卧佛绿色颜料氯砷钠铜石和白色颜料砷铅矿均属于砷酸盐类物质,其矿物属于自然界中稀少的次生矿,这些颜料可能是由其他颜料转化而来。在大足卧佛的各色颜料中,蓝色和红色颜料更易滋生霉斑,特别是蓝色颜料长霉最为严重,而含铅铜砷的绿色和白色颜料表面几乎不长霉,推测可能与铅、铜重金属盐和砷元素的强毒性有关,并指出不同颜料对微生物活性的影响存在差异,该研究为大足石刻彩绘颜料鉴定、修复材料选择及保护修缮提供了科
Niche of Sakyamuni Eentering Nirvana(Sleeping Buddha)at Baoding mountain,Dazu District,Chongqing,is the largest statue in Dazu rock carvings,one of the world cultural heritage,and also the world’s largest Buddha statue featuring only the upper part of the body.Suffered from the influence of natural power and human factors for thousands of years,various diseases such as paint scaling and biological colonization appeared on the surface of the Sleeping Buddha.To achieve the conservation and restoration of“raw materials and original technology”,it is necessary to identify the pigments of the statue.The surface pigments and the priming coat material of the Buddha were identified by means of micro-Raman spectroscopy(μ-Raman)and other techniques.Furthermore,the possible sources of white and green pigments,the relationship between pigment types and mildew have been discussed.The experimental results have shown that the back of each surface pigment of the Sleeping Buddha based on white priming coat material.The Raman spectrum of the priming coat material shows an intense band at 1006 cm^-1 without other additional bands,which is the characteristic band of gypsum,that indicated the primer material is gypsum(CaSO 4·2H 2O)with high-purity.The surface of the statue is decorated with red,blue,white,and green pigments.The red was identified to be red ochre(Fe 2O 3),with stable property and widely used in various painted relics,such as murals and painted pottery.Combined analysis by polarized light microscopy,the blue was identified to be synthetic ultramarine blue(Na 6-10 Al 6Si 6O 24 S 2-4),with uniform particles and averaging less than 5μm in diameter.The white was identified to be a mixture of cerussite lead white(PbCO 3)and mimetesite(Pb 5(AsO 4)3Cl).Among white pigments,lead white is common,while mimetesite is infrequent.In particular,mimetesite is discovered as pigment for the first time at Dazu rock carvings.The Raman spectrum of green pigment displays intense bands at 859 cm^-1,attributed to the AsO-4 stretchin
作者
王丽琴
马彦妮
张亚旭
赵星
何秋菊
郭金沂
任翰霆
WANG Li-qin;MA Yan-ni;ZHANG Ya-xu;ZHAO Xing;HE Qiu-ju;GUO Jin-yi;REN Han-ting(College of Cultural Heritage,Northwest University,Xi’an 710069,China;Shaanxi Academy of Archaeology,Xi’an 710054,China;Department of Conservation and Restoration of Cultural Heritage,Capital Museum,Beijing 100045,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2020年第10期3199-3204,共6页
Spectroscopy and Spectral Analysis
基金
国家自然科学基金项目(21175104)
陕西省重点研发计划项目(2019ZDLSF07-05)
西北大学文化遗产学院研究生创新项目(2019WYYCY-02)资助。
关键词
拉曼光谱
颜料
大足卧佛
文物保护
材质分析
Micro-Raman spectroscopy
Pigment
Sleeping Buddha at Dazu Rock Carvings
Relics conservation
Material analysis
