Bersani D, Campani E, Casoli A, Lottici P P, Marino I-G
Dipartimento di Fisica, University of Parma, Viale G.P. Usberti 7/a, 43100 Parma, Italy.
Anal Chim Acta. 2008 Mar 3;610(1):74-9. doi: 10.1016/j.aca.2008.01.041. Epub 2008 Jan 20.
Two holy water fonts (dated at the beginning of the XVII century) in the Santa Maria della Steccata Church in Parma (Italy) have recently been restored. Before the intervention, a detailed investigation on their degradation products was carried out to understand the mechanisms of alteration of the materials and to suggest appropriate restoration procedures. The analyses were performed by means of powder X-ray diffraction (XRD), micro-Fourier transform infrared (FTIR) and micro-Raman spectroscopies. Calcite, iron oxides, silicates and sodium chloride (from salted holy water) were found in the red coloured calcarenite. On and under the lead coverings, different lead oxides (mainly massicot), other lead salts (lead basic carbonate, cerussite, plumbonacrite Pb10O(OH)6(CO3)6 and lead-chlorine compounds as laurionite PbOHCl and phosgenite Pb2CO3Cl2) were identified by Raman spectroscopy and XRD. Haematite alpha-Fe2O3, goethite alpha-FeO(OH) and lepidocrocite gamma-FeO(OH) were found on and around the iron hinges. Lead compounds and sodium chloride, through crystallization and solubilization cycles, were responsible for the stone's degradation, whereas the iron corrosion materials on the hinges produced mechanical stress and cracks in the stone. Various suggestions have been given on how to restore these fonts and to remove the causes of damage.
意大利帕尔马的圣玛丽亚·德拉·斯特卡塔教堂内有两尊圣水钵（可追溯至17世纪初）最近得到了修复。在修复之前，对其降解产物进行了详细调查，以了解材料的变质机制并提出适当的修复程序。分析通过粉末X射线衍射（XRD）、微傅里叶变换红外（FTIR）和微拉曼光谱进行。在红色钙质砂岩石中发现了方解石、氧化铁、硅酸盐和氯化钠（来自加盐的圣水）。通过拉曼光谱和XRD在铅覆盖层及其下方鉴定出了不同的铅氧化物（主要是密陀僧）、其他铅盐（碱式碳酸铅、白铅矿、六羟碳酸铅铅矿Pb10O(OH)6(CO3)6以及铅氯化合物如羟氯铅矿PbOHCl和氯铅矿Pb2CO3Cl2）。在铁铰链及其周围发现了赤铁矿α-Fe2O3、针铁矿α-FeO(OH)和纤铁矿γ-FeO(OH)。铅化合物和氯化钠通过结晶和溶解循环导致了石材的降解，而铰链上的铁腐蚀物质在石材中产生了机械应力和裂缝。针对如何修复这些圣水钵以及消除损坏原因提出了各种建议。
