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Dalian Island, located in the northwest of Pingtan County, Fujian Province, China, has been an important junction on the Maritime Silk Road since the Tang dynasty. This study focuses on sauce-glazed ceramic ware from the Song dynasty salvaged from the waters near Dalian Island Wharf. The composition, phase attributes, and microstructures of the marine organism remains attached to the ceramic ware were analyzed using an optical microscope, scanning electron microscope, and micro-Raman spectrometer to investigate the influence of marine organisms on the degradation of the ceramic ware. Long-term abrasion by sea wave-borne debris led to the increased surface roughness and wettability of the ceramic ware, facilitating the attachment of marine organisms. Differences in surface roughness between the inner and outer walls led to varying levels of biomass. Coralline algae secreted inducers to attract the larvae of macrofoulers. The attachment of different types of marine organisms had varying effects on the degradation of the ceramic ware. Firmly attached unitary organisms could alleviate the scouring of sea wave-borne debris and hinder the intrusion of foreign pollutants, thereby playing a 'bio-protective' role. In contrast, the group skeletons of modular organisms could reinforce the mechanically damaged surface but failed to block the intrusion of iron rust and other pollutants, resulting in chemical alterations of the glaze. Therefore, the specific species of the attached marine organisms should be considered in subsequent conservation efforts. [ABSTRACT FROM AUTHOR]

Dalian Island is located in the sea area near Pingtan County, Fujian, Southeast China. The sea area used to be the junction of the eastern and western ship routes on the Maritime Silk Road, and is also an important region for underwater archaeology in China. This study focused on a sauce-glazed ware of the Song Dynasty, with serious degradation, which was salvaged out of the water at the Dalian Island Wharf. Optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and micro-Raman spectroscopy were used to comprehensively analyze the composition, phase attributes and microstructure of the ware and the surface-attached coagula. The findings revealed that the sea wave-borne debris scoured the surface of the ware, causing mechanical damage to varying degrees and a significant decrease in its degradation resistance. This was the primary factor accounting for the poor preservation state of the salvaged ceramic ware, and the precondition for the subsequent attachment of marine organisms and the deposition of inorganic pollutants. The calcareous skeletons formed on the surface induced by the bio-mineralization of coralline algae (a type of marine plant) could resist the mechanical action caused by the motion of sea waves, thereby slowing down the ware's degradation process. In other words, the calcareous skeletons played a 'bio-protective' role to a certain degree. In addition, inorganic pollutants represented by iron rusts also participated in the corrosion of the glaze. Some pollutants were directly deposited on the pits and cracks on the surface of the ware, which brought stress to the glaze and glaze/body interface, causing the glaze to further crack and spall. Moreover, iron rusts reacted with the glaze, leading to chemical alteration, accompanied by the formation of iron silicate as the alteration product. Anorthite crystals in the interlayer did not participate in the reaction but remained at the original position. The alteration product gradually replaced the original glass phase of the glaze and entered into the body via pores and cracks. In conclusion, the complex degradation morphology of the salvaged sauce-glazed ware could be attributed to the combined action of mechanical damage, marine bio-fouling, and chemical alteration. [ABSTRACT FROM AUTHOR]

The Ru kiln is a famous kiln that originated in the Northern Song Dynasty (960–1127 CE) in China. After nearly a thousand years of degradation, many 'white spots' have appeared on the Ru glazes, which have seriously damaged the visual aesthetic. Energy-dispersive X-ray fluorescence spectroscopy (EDXRF), X-ray diffraction analysis (XRD), optical microscopy (OM), scanning electron microscopy-energy dispersive spectrometry (SEM–EDS), Raman spectroscopy, and angle-resolved spectrum system were used to systematically investigate the composition, microstructure, and degradation morphology of the Ru ware. The degradation mechanism of the Ru glaze was investigated, showing that the heterogeneity of the glaze microstructure resulted in different degradation morphologies. The weakest part determined the overall corrosion resistance. Fine crackles of the glaze provided a fast path for corrosion. The special soil environment at the Qingliangsi site was a key influencing factor leading to the ubiquitous and severe degradation of the Ru wares. The microstructure degradation caused by chemical corrosion provided complex light-reflecting interfaces, leading to the formation of 'white spots' on the surface. Combined with the influence of exotic contaminants, the color and texture of the Ru glaze significantly changed, and the appearance quality seriously declined. [ABSTRACT FROM AUTHOR]