Characterization of White and Black Deposits on the Surface of Korean Stone Cultural Heritages

Abstract

White and black deposits have been frequently observed on the surface of Korean stone cultural heritages, and they are considered as damage factors in both conservation and esthetic points of view. In order to set up the appropriate conservation remedy, it is important to know their origins, characteristics, and compositions. In this study, optical and scanning electron microscopes~SEMs! equipped with an energydispersive spectrometer~EDS! and X-ray diffractometer were employed to determine the white and black deposits. It was found that both deposits consisted mainly of calcium carbonate~calcite! and calcium sulfatẽ gypsum!. The calcite and gypsum were characterized by bladed, rhombohedral, tabular, and amorphous morphologies under a SEM. The black deposit was not only composed of calcite or gypsum, but also accompanied amorphous and irregular matrix. SEM-EDS analysis revealed an abundance of silicon, aluminum, iron, phosphorus, and carbon on the matrix, which were major elements of soil, atmospheric deposits, and organisms. The white deposit, on the other hand, barely contained those coloring substances. These salts and deposited substances were caused by chemical reaction and physical adhesion between rock-forming minerals, lime mortar, sulfur in polluted air environment, soil dust, and microorganisms.

Laminar gypsum crust on lede stone: Microspatial characterization and laboratory acid weathering

“…The formation of gypsum crusts on Lede stone was recently studied on the micro-scale in laboratory conditions [16,17]. In the present study, current methods as thin section microscopy and SEM-BSE and -EDX, which have typically been used for describing gypsum crusts [30,44,50], are multidisciplinary combined with advanced methods such as X-ray computed microtomography (µCT) [10,29], X-ray fluorescence micromapping (µXRF) [9] and the scratch test [36]. The aim is to study the chemical and physical relation between the laminar gypsum crust and the underlying sandy limestone, and to explore the benefits of these techniques for the characterization of altered rocks in laboratory, as well as for the interpretation of field tests.…”

Spanish and Portuguese Gilding Threads: Characterization Using Microscopic Techniques

“…Microscopy techniques and microanalyses using optical microscopy and scanning electron microscopy (SEM) combined with energy-dispersive X-ray spectrometry (EDS) and wavelength-dispersive spectrometry are excellent tools for studying materials from cultural heritage (Alves et al, 2013; Kim et al, 2013; Ravines et al, 2016). These techniques have mostly been used for the characterization of gilded threads (Hacke et al, 2004; Karatzani, 2008; Rezic et al, 2010; Balta et al, 2015).…”

Conservation Treatment, Deterioration Assessment and Petrography of the Hongjimun Ogansumun (Five-arched Floodgates) in Seoul

“…이를 EDS로 분석한 결과, 소량의 나트륨, 칼륨 및 황이 검출되 었다( Figure 7F) Figure 7. Scanning electron microscopic images, EDS analysis and X-ray diffraction patterns of the white contaminants on the Ogansumun (partly modified Kim et al, 2013). (A, B, C) HP-1.…”