Abstract:Sand pottery is a very important kind of pottery that was widely used as daily utensils (especially for cooking) by ancient peoples. In this study, we used confocal micro-Raman spectrometry to analyze the admixture of the sand potteries unearthed from the Xipo Site in Lingbao, Henan province. We discuss the types, proportions and sources of the minerals. The results show that the admixture of the reddish-brown sand potteries unearthed at the Xipo Site include mainly feldspar, quartz and mica. The results also show that the proportion of sandy minerals used in some samples can reach about 20%. Moreover, analysis of the stone unearthed from the site shows that its phase composition is similar to the admixture found in the pots. In addition, based also on the analysis of sand pottery from the Liangzhu Ancient City Site, we propose that part of the ancient sand pottery admixture was likely to have come from processing wastes of stone tools and jade wares.

Abstract:In order to study the deterioration of the polychrome potteries excavated from Chu (one of the states in the Warring States Period) tombs of the Chengyangcheng Site in Xinyang, Henan, we used X-ray fluorescence (XRF), infrared (IR) and Raman spectrometry to analyze mineral pigments of the pottery surfaces and metal coatings. The results show that this batch of potteries belongs to typical northern type, having high silica but low alumina, high water absorption rates, relatively looser structures, and firing temperatures ranging from 930℃ to 1025℃. The red pigments of the pottery surfaces are mainly cinnabar and hematite, and the yellow ones are goethite. The metal coatings of some painted potteries from Tomb No.8 contain tin (Sn). This research could provide a scientific basis for cultural relic conservation and restoration in the future.

Abstract:In this work, the Five-Dynasty sky-green porcelains of the Yaozhou Kiln were studied. In order to investigate the coloring and translucency mechanism in the sky-green porcelains, we analyzed the chemical composition, phase, chemical state of the coloring elements and microstructure, using energy-dispersive X-ray fluorescence (EDXRF), X-ray diffraction (XRD), X-ray photoelectron spectrometry (XPS) and scanning electron microscopy-energy dispersive spectrometry (SEM-EDS). The results indicate that the main colorant is ferric oxide (Fe₂O₃), and that the scattering effect of the physical structures (residual crystals and phase separation droplets) can deepen or weaken the chemical color in the glaze. Furthermore, this scattering effect also affects the color saturation and opacity of glaze surfaces to some extent. Analysis of the white body indicates that the translucency is related to the absorption effect of coloring oxides and the scattering effect of crystal boundaries and residual micropores. Low contents of ferric oxide (Fe₂O₃) and ferrotitanium solid solution greatly decreased the absorption of incident light. In addition, small amounts of crystal boundaries and residual bubbles also weaken the scattering of incident light. As a result, the sky-green porcelains exhibit good translucence.

Abstract:Our study samples, bought and collected at the Jingdezhen Morning Market, were famille-rose porcelains or broken shards of various periods. An Eagle Ⅲ-type energy-dispersive X-ray fluorescence (EDXRF) spectrometer was employed to analyze the primary and secondary chemical compositions of the famille-rose porcelain samples of different periods. In addition, we compared the similarities and differences in their chemical compositions using multivariate statistical analysis methods. The analytical results support the conclusion that Jingdezhen famille-rose porcelains were born in the reign of Kangxi, matured and culminated respectively in the reigns of Yongzheng and Qianlong, but then receded gradually. We also made some inferences: 1) the pigment formulas of famille-rose porcelains from imperial and folk kilns were statistically different during the reigns of Kangxi, Yongzheng and Qianlong; 2) the famille-rose pigment formula was inherited and also innovated during the Minguo period; 3) the purple color of early famille-rose porcelains was mixed with red, blue and green colors.

Abstract:Identification of the provenances of ancient ceramics is always a key job in research on ancient ceramics. Besides traditional visual identification methods by shape, decorative patterns and glaze color, etc., modern technological methods have also been developed in recent years to determine the provenances of ancient ceramics. These technological methods are mainly based on the elemental compositions of ancient ceramics, especially on typical trace elements. However, some ceramics having similar elemental compositions are imitations, so multiple types of evidence are needed to determine their provenances. In our research, the ceramic samples include authentic ones collected from four typical ancient kilns of South and North China: Yue Kiln, Jian Kiln, Yaozhou Kiln and Ding Kiln as well as some imitations. X-ray fluorescence (XRF) and thermoluminescence (TL) technologies were respectively used to determine elemental compositions of the glazes and their thermoluminescent characteristics, with the aim of determining their provenances. The analytical results show that ancient ceramics from the same area share similar chemical compositions, typical trace elements and thermoluminescent (TL) properties. More manganese (Mn) and phosphorus (P) was detected in the samples of Yue porcelains, which is thought to be related to the local plant ash used for porcelain-making. Yue porcelains also feature high thermoluminescent sensitivity, with the peak value above 5000 cps. A high content of aluminum (Al) in the body is the characteristic of the ceramics from Ding and Yaozhou Kilns, and can be used to differentiate them from Yue and Jian ceramics. Higher silicon (Si) and magnesium (Mg) but lower calcium (Ca) and manganese (Mn) contents are the characteristics of Ding porcelains and are distinct from the others. Furthermore, the Yue porcelains have the highest TL sensitivity among the four kilns. Therefore, ancient ceramics from different provenances can be distinguished according to different elemental compositions and TL sensitivities.

Abstract:Sixty three porcelain shards and four brick and tile samples unearthed from the Qinglong Town Archaeological Site in Shanghai were studied in this research. The thermoluminescence (TL) pre-dose technique was applied to acquire the paleo-dose of porcelain samples. The fine grain technique was applied to acquire the paleo-dose of brick and tile samples. The thick source α-counting method and X-ray fluorescence (XRF) spectrometry were used to acquire the annual dose of the samples. The TL dating results indicate that the porcelain samples were from the Tang Dynasty to the Southern Song Dynasty. The brick and tile samples dated back to the Northern Song Dynasty, which is consistent with what was recorded in the historical literature about the first construction years of the Longping Temple Pagoda.

Abstract:A number of Mi’se porcelains have been unearthed at Shanglin Lake, Zhejiang Province. These porcelains discussed here are similar to those excavated from the underground palace of Famen Temple in terms of appearance and shape, as well as stacking and firing methods. Through field investigation into the kiln site and scientific tests, including thermoluminescence (TL) dating, energy dispersive X-ray fluorescence (EDXRF) of chemical composition analysis, microstructural analysis and apparent porosity testing of the samples, we find that this batch of Mi’se porcelains is similar to Yue Kiln porcelains, in general, in terms of chemical composition and microstructure. Therefore, it is impossible to distinguish Mi’se porcelains from average Yue Kiln porcelains in these two respects. However, with regard to technology, Mi’se porcelains boast some superior characteristics, in that the materials were processed with more attention to details, the bodies were trimmed in a more meticulous way, glaze was applied more evenly and symmetrically, and porcelain saggers were used for stacking and firing. These studies indicate that Mi’se porcelains are high-quality products of Yue Kiln and were made using advanced technologies.

Abstract:The object of our study was the “Huangyan Shabu Kiln Sites” in Zhejiang province. We investigated the Shabu Sites and the surrounding areas and also took some typical celadon samples through archaeological field surveys. We then used archaeometric methods to study the product characteristics, porcelain-making technologies, and the production time of the kilns. The internal structures of the body and glaze of the celadons unearthed from Huangyan were analyzed by optical microscopy. The chronological age of these typical celadon samples was determined using thermoluminescence. The chemical compositions of the body and glaze of samples from both Huangyan and Shanglin Lake were determined by energy dispersive X-ray fluorescence (EDXRF) and compared. In addition, by comparative study of the characteristics of Yue ware, we found the samples from the Huangyan Kiln were basically in line with the products of Yue ware system, in terms of raw materials, fuels, furnace structures, shape features, decorative arts and processing technologies. The study results show that the Huangyan Shabu Kilns in Zhejiang province are important kiln remains dating from the late Tang Dynasty to the Southern Song Dynasty. They belong to Yue ware system and show high ceramic-firing skills and significant archaeological research values.

Abstract:Clay used as the raw material for pottery, and unfired pottery billets were found at the Guanzhuang Site in Xingyang, Henan province. This excavation provides precious research materials for the study of Zhongyuan (the central plains of China) pottery-making technologies used after the middle of the Western Zhou Dynasty. In this study, we analyzed some raw materials and pottery billets using energy dispersive X-ray fluorescence (EDXRF) and X-ray diffraction (XRD) methods, and conducted re-sintering experiments on the clay in a muffle furnace. The experiments show that the iron content of the pottery raw materials from the Guanzhuang Site is high, with some iron minerals such as magnetite precipitating during firing, and that the pottery color is deep. In addition, the homogeneity of the phases and the clustering features of the chemical compositions between the raw materials and the potteries of the same period indicate the local characteristics of pottery production. This work provides basic information on pottery-making technologies from the late Western Zhou Dynasty to the early Spring and Autumn Period.

Abstract:In order to study the raw materials and technical processes used for ancient porcelains unearthed from Gongyi Kiln in Henan Province and Xing Kiln in Hebei Province, and also to investigate the technical connection between the two kilns, we selected the celadons and white porcelains produced in the Northern, Sui and Tang Dynasties and conducted microscopic observations and electron probe microanalysis (EPMA). The results indicate that there are some differences in the raw materials used for the bodies and glazes of porcelain samples from the two kilns. For Gongyi Kiln, local kaolin clay is the only ingredient used for porcelain bodies, whereas the glaze includes high-calcium (Ca) plant ash in addition to the raw material used in the porcelain bodies. In the case of Xing Kiln, local kaolin clay and feldspar mineral are used for porcelain bodies, and the glaze contains not only clay but also plant ash or minerals with high contents of calcium (Ca) and magnesium (Mg). However, the products of Gongyi and Xing Kilns still share some similarities, such as appearance and shape as well as the use of certain raw materials (e.g., addition of quartz mineral to the glaze). It can be inferred that Gongyi and Xing Kilns had close communications in terms of raw materials and techniques for porcelain making.

Abstract:In order to explore nondestructive methods to analyze colored Chinese porcelains, we used spectroscopy and optical methods to reveal the macroscopic and microscopic characteristics of two kinds of famous colored porcelains, namely, Doucai (clashing color porcelain) and famille-rose porcelain. We also discuss the technology used to make them. We carried out comprehensive analyses on four Doucai shards from Jingdezhen, Jiangxi Province, and two shard samples with famille-rose decoration from Xinjiang County, Shanxi province, using individual point sampling and comparative study. With the aid of multi-spectral imaging, stereomicroscopy, optical coherence tomography (OCT), X-ray fluorescence spectrometry (XRF) and laser Raman spectrometry, we found that the two kinds of porcelains obviously differ in the chemical compositions of their over-glaze decorations and ceramic glazes. The over-glaze decorations of the Doucai contain a high content of lead, whereas those of the famille-rose porcelains contain arsenic besides lead. For the Doucai, the deep red, green and blue over-glaze decorations were colored respectively with hematite, copper iron and cobalt. For the famille-rose porcelains, the red over-glaze decorations were colored with hematite and the deep red one with cinnabar. Multi-spectral imaging technology was applied to identify and analyze some hidden image information about the over-glaze decoration, and OCT was used to visually observe the cross-section structure of the over-glaze decorations. This study provides a scientific basis for the identification of the porcelain-making technologies of the early porcelains with over-glaze decorations, and also provides a useful methodological reference for the future scientific research. Therefore, the scientific analyses of these two kinds of distinctive porcelains are of great significance in understanding the development of ancient ceramic technologies of China.

Abstract:Glazed pottery is an important category in the history of Chinese ceramics, especially in the Ming Dynasty. Glazed Ming pottery was made in quantities and unique styles, according to the desires of the aristocracy and common people at that time. In recent decades, archaeologists have found large amounts of Ming glazed potteries, which have enhanced our knowledge and understanding of them accordingly. This essay, which is based on archaeological findings and historical documents, represents a comprehensive study of Ming glazed potteries. Architectural units and burial figurines for the court and princes are discussed, as are glazed figurines and other related vessels for ordinary people. In addition, the author of this essay probes into some pertinent questions.

Abstract:There is no significant difference in the general practice of porcelain restoration in China and other countries. However, there are a wider variety of commercial products specially designed for porcelain restoration in western countries. Many of those products are quite worthy of being introduced into China. In this study, we tested and studied three imported products: Hxtal NYL-1, Golden Porcelain Restoration Glaze and Golden Polymer Varnish with UVLS. Tensile test results show that Hxtal NYL-1 has the highest elongation at breakage and the lowest tensile strength among five epoxy formulations. After 78-day exposure to UV light at 365 nm, the color of Hxtal NYL-1 varies the least among three epoxy formulations. According to the UV-Vis spectra, Golden Glaze only absorbs UVB, and Golden Varnish absorbs both UVB and UVA. The results of a 7-day UV light aging experiment show that neither Golden Glaze nor Golden Varnish becomes yellow after being exposed to UV light at 365 nm, but Golden Varnish is much less prone to yellowing than Golden Glaze at 254 nm. In addition, based on some practical cases, the usage of these products in porcelain restoration is also briefly introduced in this paper.

Abstract:The theory of colorimetry is well developed and has been applied in the field of cultural relic conservation and restoration. With the advantages of being accurate and quantitative, this method is not susceptible to subjective influence. Restoration effects on ancient ceramics are greatly affected by light sources. Unsatisfactory visual effects of restoration may occur if the light sources of the repair room and the exhibition hall do not match each other. In our study, according to the theory of colorimetry, we improved the color-rendering performances of objects under different light sources with the aid of colorimeter. This work paves the way for quantitative coloring in the future.

Abstract:It is generally acknowledged that porcelains, among portable antiquities, boast relatively stable physical and chemical properties. However, porcelains from sea water are likely to suffer from deterioration such as salting out, attachment and corrosion due to the complicated burial environments. In the course of conservation and restoration, some natural diseases are easily mistaken for production defects. In order to preserve as much historical information about the antiquities as possible during the clean-up process, we systematically examined traditional porcelain production methods used at the Jingdezhen Kiln, and conducted further research on typical production flaws that can easily be confused with the natural diseases. Based on these traditional methods and compositional characteristics of porcelains, we provide some guidance on the selection of clean-up methods and repair materials used for porcelains. From the perspective of identifiability and ageing resistance, this paper focuses on discussing the restoration scale of porcelains exhibited in museums. Based on our practical work, we discuss some problems that should be noticed in restoration and also provide an outlook for the future practical work and research.