中国古代高温铁釉瓷的呈色研究

中国是最早烧制高温陶瓷的国家,从原始瓷开始,含铁原料制作的颜色釉瓷贯穿了整个中国制瓷的历史,从而产生了呈色各异、品种繁多的铁釉瓷.为研究影响铁釉瓷呈色的各类因素,本工作综合应用成分分析方法,对一些典型的铁釉瓷品种进行定量测定.研究表明:高温铁釉中Fe2O3的含量范围从1％至高达约18％,铁的含量对釉的呈色起着决定性的作用;同时窑炉的烧成气氛和原料中的TiO2含量变化会影响Fe2+、Fe3+的生成比例,从而使釉色发生改变;另外,原料中MnO的含量、施釉工艺等也会对釉色产生影响.研究结果将对我国高温铁釉瓷制作技术的产生、发展有一个更好的诠释.     

Evaluation of Quantitative XRF Analysis Applied to Determine Cobalt Sources in Chinese Blue‐and‐White Porcelain

A method using the ratios between MnO, Fe₂O₃ and CoO to differentiate the cobalt sources for Chinese blue‐and‐white porcelain was developed in Oxford in the 1950s using X‐ray fluorescence (XRF) analysis directly on the glaze. In this paper, six blue‐and‐white porcelain sherds from the Luomaqiao kiln were analysed by XRF on the glaze and by scanning electron microscopy with energy‐dispersive spectrometry (SEM‐EDS) in cross‐section. The ratios between MnO, Fe₂O₃ and CoO calculated by quantitative XRF and EDS analyses are different. The analysis depths for MnO, Fe₂O₃ and CoO are < 60 μm by XRF analysis. However, the average glaze thickness of samples is > 400 μm, and the MnO, Fe₂O₃ and CoO mainly remain in the lower layer of the glaze, which is beyond the analysis depths of XRF analysis. The limitations of major and minor quantitative analyses for differentiating cobalt sources are discussed.     

临水窑与介休窑白底彩绘工艺的对比研究

白底黑花装饰风格的瓷器,始终是陶瓷、科技界和陶瓷爱好者关注的热点。临水窑(磁州窑)与介休窑白底黑花风格的瓷器之间有着密切的联系,但是对于两窑产品的科技分析甚少,至于两者的对比研究更是无从谈起。因此,本工作利用岩相分析、SEM-EDS等方法分析了临水窑(磁州窑)、介休窑样品的瓷胎、化妆土及瓷釉的化学成分和显微结构。比较分析显示,两窑样品的瓷胎均为低硅高铝配方,且介休窑瓷胎中的Al2O3含量更高;两窑瓷胎粗糙,Fe2O3、TiO2含量较高,致使其呈浅黄色。瓷胎表面均施有化妆土,所不同的是,介休窑的瓷胎表面施有两层化妆土,其靠近釉的一层化妆土(h2),Fe2O3、TiO2含量极低,靠近胎的一层化妆土(h1),Fe2O3、TiO2含量较高;临水窑样品的瓷胎表面仅施一层化妆土,其Fe2O3、TiO2含量较低,但高于介休窑近釉层化妆土中的相应含量。介休窑瓷釉为典型的高钙釉,而临水窑则为典型的碱钙釉和钙碱釉。不难认识到,介休窑似在临水窑白底黑花及化妆土工艺的基础上,因地制宜,勇于创新,形成了成本低廉、技术先进的两层化妆土工艺,在当地原料较为粗糙的条件下,生产出质量较好的白底釉下彩绘瓷器。     

安徽铜陵师姑墩遗址出土原始瓷的初步分析研究

通过对铜陵师姑墩遗址出土的29件原始瓷进行的检测分析表明,师姑墩原始瓷胎为高硅低铝型,部分器物胎体的Fe_2O_3和TiO_2含量较高;釉属高温钙釉,釉中Mn和P含量相对较高,其可能由草木灰引入,部分器物釉中含较高的Fe_2O_3,致使釉色较深。这一结果为皖南地区先秦时期原始瓷手工业发展研究提供了新的科学依据。     

TECHNOLOGY AND COLOUR DEVELOPMENT OF HISPANO-MORESQUE LEAD-GLAZED POTTERY

Lead-glazed pottery from the medieval workshop of Les Olleries Majors (Paterna, Spain) has been studied by Mössbauer spectroscopy, X-ray diffraction, X-ray fluorescence and optical spectroscopy. Yellow, brown and honey-coloured glazes occur on pots glazed on only one surface. They have virtually identical compositions and transmittance spectra, their apparent differences in colour are due to the colours of the underlying pastes. Yellow glazes occur on cream-coloured calcareous bodies, honey-coloured glazes occur on less calcareous bodies with some development of hematite, while brown glazes occur on red siliceous cooking-pots. Green glazes are found on pots glazed on both surfaces; the glazes trapped CO₂ evolved by decomposing carbonates, resulting in an internal reducing environment. This caused the reduction of iron to the ferrous state which coloured the glaze green by diffusion.     

Lead‐Glazed Rustiques Figulines (Rustic Ceramics) of Bernard Palissy (1510–90) and his Followers

The glaze chemistry of a group of rustiques figulines attributed to the renowned French potter Bernard Palissy (1510–90), or to his followers and imitators, has been determined non‐destructively using PIXE and PIGE analyses. The glazes are all lead silicates, the colourants being transition metal oxides—CuO, CoO, MnO and Fe₂O₃—with a small addition of SnO₂ to some of the glazes being common. Some distinction can be made between the various fabricated objects based on details of the overall composition and on the concentrations of the various colourants. The presence of B₂O₃ in any glaze, even in quantities as small as 0.1–0.3%, indicates a post‐16th century production. Additionally, B₂O₃ in larger quantities, a few per cent or greater, very probably indicates an 18th–19th century production. However, at least one object known to be of 19th century production contains no B₂O₃.     

A Study on Black‐Body Celadon Excavated in The Altar Guan and Literature Ge (Longquan Ge) Kilns by EDXRF

Samples of celadon were collected from the Altar Guan Kiln in Hangzhou, and from the Xiaomeizhen and Xikou Kilns, two subordinate kilns of the Longquan Kiln producing black‐body celadon called Literature Ge. Both the elemental contents in the sample bodies and the glaze were measured. The results reveal that the sample bodies contain fingerprint information for provenance, while this was lost in the glaze during the production process. The TiO₂, MnO and Rb₂O contained in the bodies are fingerprints to distinguish between celadons from the Xiaomeizhen and Xikou Kilns. In the Altar Guan Kiln, some low‐TiO₂ samples were found and their body colour is much lighter than some others, but they do not differ with regard to iron content. This indicates that both titanium and iron are indispensable for the blackness of the bodies: they may react to form some black minerals during the firing process. Ultimately, samples from the Literature Ge and Altar Guan Kilns differ in their body constituents. Principal component analysis reveals that the samples can be divided into two groups, corresponding to the two different areas.     

Iron-57 Mössbauer spectral studies of medieval stained glass

⁵⁷Fe Mössbauer spectral data for six excavated and two simulated medieval stained glass samples are reported. Iron-containing precipitates are observed in the two simulated medieval glasses and are responsible for the amber colour of these samples. The ferrous/ferric ratio of the other samples is dependent on the glass composition and glass making conditions. The green glasses are associated with the presence of both ferrous and ferric iron, the ratio being very similar in three of the glasses studied, while in the purple and emerald green glasses the iron which is constitutionally incorporated in the glass is solely in the ferric oxidation state. The UVvisible spectra of some of the glasses are used to assist in interpretation of the colourant action of iron, and the role of Mössbauer spectroscopy in linking separate glass fragments with a common source is also indicated.     

氧化铁及分相结构对钧窑蓝色系釉的呈色作用

钧窑大部分产品的基本釉色之一是各种浓淡不一的蓝色乳光釉。为了探讨釉层呈乳光蓝色及其深浅的原因,利用聚焦离子束、场发射扫描电镜(配备EDS)、高分辨率透射电镜(配备EDS)、穆斯堡尔谱仪以及紫外可见分光光度计等手段,对7片出土于河南禹县钧窑遗址的具有深浅不一蓝色釉层的残片样品进行科学分析。结果发现,钧窑蓝色系釉层的主要着色剂为Fe2+,其含量的增加能够使釉面蓝色饱和度增大;此外,釉层中存在着大小不一的分相液滴,小液滴尺寸增大,能够使蓝色釉面颜色偏绿、明度提高。即钧窑蓝色乳光釉的呈色是化学成分和显微结构的共同作用,也是对可见光散射和吸收共同作用的结果。     

五代耀州窑天青瓷的研究

为揭示五代天青瓷釉的呈色机理以及胎体的透光机理,本研究以五代耀州窑天青瓷为主要对象,分别采用EDXRF、XRD、XPS和SEM/EDS等测试方法,分析了化学组成、物相、着色元素的化学状态及微观结构对瓷釉的呈色及瓷胎透光性的影响。结果表明,天青瓷釉为复合呈色方式,釉中Fe_2O_3产生的化学着色作用和釉层中物理结构(残余晶体和分相液滴)对入射光的散射作用产生的结构色,或加深或淡化了呈色,且对釉面的色饱和度和乳浊度也有一定的影响。天青瓷胎的透光性主要与着色氧化物对入射光的吸收以及晶界、气泡对入射光的散射有关。低含量的Fe_2O_3和铁钛固溶体,大大减少了其对入射光的吸收。同时,较少的晶界也减弱了对入射光的散射。因此,天青瓷的透光性良好。     

Early Opacifiers In The Glaze Industry Of First Millennium bc Persia: Persepolis And Tepe Rabat

This study characterizes the opacifiers and colouring agents used in the glazed bricks of Persepolis (mid‐first millennium bc ) and the Mannean site of Tepe Rabat in north‐western Iran (eighth to seventh centuries bc ). Various analytical studies show that lead antimonate and brizziite (NaSbO₃) were used as the yellow and white opacifiers in the glazes of Persepolis and Tepe Rabat. Brizziite is shown to be incorporated in the white, green and turquoise glazes, and is also associated with lead antimonate and CaSb₂O₆ in some yellow and white opacifiers. The simultaneous formation of these opacifiers in one glaze might have been accidental. A possible connection between the Achaemenid glaze industry and the Mannean glaze production at Tepe Rabat is discussed.     

AN ANALYSIS OF THE GEM‐BLUE GLAZE OF YE WANG'S KOJI POTTERY*

Koji pottery is a glazed ceramic art used widely for figurines. In early Taiwan, it was employed in temple construction for decorative purposes. Ye Wang (1826–87) is the first historically documented Koji artist of Taiwan and also the most prominent Koji pottery artist, noted for his modelling and glazing skills. Unfortunately, his unique technique was lost following his death in 1887. In order to provide vital information for ongoing conservation work on Koji pottery, this study analysed the physical and chemical characteristics of Ye Wang's gem‐blue glaze, to discover the glaze formula. DSC combined with the two‐thirds rule revealed that the firing temperature of Ye Wang's works of art was most probably around 878–923°C. EPMA revealed that the gem‐blue glaze has high alkali levels, and belongs to the PbO–K₂O–B₂O₃–Na₂O–SiO₂ system, deriving its unique colour from copper, iron, manganese and cobalt. This study found high potassium levels in the gem‐blue glaze, which are generally a characteristic of traditional Chinese glazes. In addition, a unique discovery of boron, commonly used in famille rose, was also identified in the glaze. By comparing spectra of historical and reconstructed glazes and adjusting the proportion of chromophoric elements, this study found a glazing formula with colours close to those of Ye Wang's gem‐blue glaze.     

Elemental Characterization by EDXRF of Imperial Longquan Celadon Porcelain Excavated from Fengdongyan Kiln,Dayao County

A mass of Longquan porcelain shards carved with ‘Guan’ or the dragon patterns were unearthed in the early Ming Dynasty layer of the Fengdongyan kiln site at Dayao County. These celadon shards were fired in the Hongwu and Yongle eras of the Ming Dynasty. In order to research the raw materials and firing technology of the imperial porcelain, 85 typical shards were analysed by energy‐dispersive X‐ray fluorescence (EDXRF). The results indicate that the contents of TiO₂ and Fe₂O₃ in the body vary in the Hongwu and Yongle eras. Compared with Longquan glazes in the Southern Song Dynasty, the average values of K₂O, Fe₂O₃ and TiO₂ are higher, but that of CaO is lower in early Ming imperial porcelain glazes. Principal components analysis (PCA) shows that different degrees of elutriation of the same raw materials are the main reason for this difference in the Hongwu and Yongle periods. However, the raw materials of imperial porcelain glazes show no obvious changes and have inherited the earlier tradition. The production and firing technology of imperial porcelain reached a higher level and had not declined in the Early Ming Dynasty.     

THE SECTILIA PANELS OF FARAGOLA (ASCOLI SATRIANO,SOUTHERN ITALY): A MULTI‐ANALYTICAL STUDY OF THE GREEN,MARBLED (GREEN AND YELLOW), BLUE AND BLACKISH GLASS SLABS

Analyses at the Cu–K, Fe–K and Mn–K edge were performed to study the green, marbled (green and yellow), blue and blackish (deep greyish olive green) glass slabs decorating three sectilia panels from the archaeological site of Faragola. Results indicate that all slabs were made by mixing siliceous sand with natron, sometimes probably mixed with small percentages of plant ash. Cu²⁺ and Pb antimonates should be responsible for the opaque green colours. The dark green and yellow portions of the marbled slabs are respectively comparable to the slabs comprising only one of these colours. Cu²⁺ together with Ca antimonates probably produced light blue slabs, whereas cobalt was used to produce dark blue slabs. We consider it possible that the abundance ratio of Fe²⁺/Fe³⁺ and the complex Fe³⁺S^2? would have an effect on the blackish slabs. The contribution of Mn cannot be ascertained even if it could have played a role in darkening glass colour. The comparison between the chemical composition of Faragola samples and several glass reference groups provided no conclusive evidence of provenance; whereas, the presence of a secondary local workshop can be hypothesized.     

Roman blue-green bottle glass: chemical–optical analysis and high temperature viscosity modelling

Chemical analysis, optical absorption spectroscopy and mathematical modelling of high temperature viscosity have been carried out on five 1st–2nd century AD Roman blue-green bottle glass fragments from Coppergate, York. Modelled viscosities indicate remarkable consistency within the sample set studied and support the suggestion that temperatures of ∼1000–1150 °C were required to remelt these glasses and to provide suitable viscosities for forming articles. Iron redox ratios (Fe²⁺/ΣFe), analysed SO₃ contents and the absence of characteristic Fe³⁺–S²⁻ amber absorption bands suggest that melting conditions for all studied glasses were mildly, rather than strongly, reducing (estimated pO₂ ≈ 10⁻¹–10⁻⁶ bar). These furnace conditions are consistent with the effects of combustion gases and carbonaceous matter contained in the raw materials.     

Study on the Material and Manufacturing Technology of Different Types of Longquan Ware Imitations from Dapu Kiln of Guangdong Province in the Ming Dynasty of China (ad 1368–1644)

Research on ancient Longquan wares and their imitations has attracted considerable attention. Using a series of experimental methods, including micro X‐ray fluorescence spectroscopy (μ‐XRF), X‐ray diffractometry (XRD), optical microscopy (OM), polarizing microscopy (PLM), dilatometry (DIL) and spectrophotometery, different samples of Longquan imitations from Dapu in Guangdong Province were collected and analysed. The study of different types of celadon from the Dapu kiln factories shows that the pale yellow body had a higher TFe₂O₃ content, and the body material must therefore have been treated differently or have come from a different source. The SiO₂ and Al₂O₃ contents in the body can be used as auxiliary parameters to identify Longquan wares and its imitations. The study also found that both kinds of glaze recipe—including calcium–alkali glaze and alkali–calcium glaze—existed in the Dapu products, which suggested that while imitating Longquan ware, the potters in Dapu also showed innovation in the recipe for the glaze material. Moreover, there were some differences in the TFe₂O₃ content, as well as the size, number and distribution of bubbles in the different types of glaze. Finally, the study revealed that the material of both the saggars and separators were composed of another porcelain clay, different from that of the celadon body. In addition, the white and compact body of the celadon had a higher firing temperature, of 1140–1187 °C, compared with other types of wares, which had a lower firing temperature of 1050–1080 °C.     

Bleached mudstone,iron concretions,and calcite veins: a natural analogue for the effects of reducing CO2‐bearing fluids on migration and mineralization of iron,sealing properties,and composition of mudstone cap rocks

This study investigates the Wangfu Depression of the Songliao Basin, China, as a natural analogue site for Fe migration (bleaching) and mineralization (formation of iron concretions) caused by reducing CO₂‐bearing fluids that leak along fractures after carbon capture, utilization, and storage. We also examined the origin of fracture‐filling calcite veins, the properties of self‐sealing fluids, the influence of fluids on the compositions of mudstone and established a bleaching model for the study area. Our results show that iron concretions are the oxidative products of precursor minerals (pyrite and siderite) during uplift and are linked to H₂S and CO₂ present in early stage fluids. The precipitation of calcite veins is the result of CO₂ degassing and is related to CO₂, CH₄, and minor heavy hydrocarbons in the main bleaching fluids. In our model, fluids preferentially enter high‐permeability fracture systems and result in the bleaching of surrounding rocks and precipitation of calcite veins. The infilling of calcite veins significantly decreases the permeability of fractures and forces the fluids to slowly enter and bleach the mudstone rocks. The Fe²⁺ released during bleaching migrates to elsewhere with the solutions or is reprecipitated in the calcite veins and iron concretions. The formation of calcite veins reduces the fracture space and effectively prevents fluid flow. The fluids have an insignificant effect on minerals within the mudstone. In terms of the chemistry of the mudstone, only the contents of Fe₂O₃, U, and Mo change significantly, with the content of U increasing in the mudstone and the contents of Fe₂O₃ and Mo decreasing during bleaching.     

IRON AND SULFUR RELATED COLORS IN ANCIENT GLASSES

Roman glass found at Jalame, in Western Galilee, and dating from the fourth century A.D., shows a variety of colors ranging from aqua blue to green to amber. It was found that the glasses are quite reduced and that the colors arise from absorptions by Fe²⁺ and a ferri-sulfide chromophore. Small amounts of colorless and purple glass, which had been oxidized by adding MnO₂, were also found.     

A STUDY ON LATE MEDIEVAL TRANSPARENT‐GLAZED POTTERY AND ARCHAIC MAJOLICA FROM ORVIETO (CENTRAL ITALY)*

Nineteen samples of medieval transparent‐glazed pottery and archaic majolica from Orvieto (central Italy) were studied. They were classified by archaeological criterion as follows: five transparent‐glazed fragments with green and brown decorations (first half of the 13th century), eight green transparent‐glazed fragments (13th century) and six tin‐glazed fragments with green and brown decorations (second half of the 13th century). SEM–EDX, XRD (the Rietveld method) and XRF were used to characterize the chemical and mineralogical compositions both of the bodies and the coatings. In all of the samples, the paste is Ca‐rich with CaO contents as high as 13–20 wt%. The mineralogical composition is compatible with a firing temperature of about 950°C, which is the typical temperature reached in a wood kiln. No difference was observed between the bodies of transparent‐ and tin‐glazed pottery. In the case of transparent glazes, the burial conditions lead to heavy weathering of the samples. However, on the basis of the analyses carried out in non‐weathered areas, the typical composition is PbO 55–65 wt%, SiO₂31–35 wt%. In tin glazes, the tin is scattered on the mass of the glaze as SnO₂crystals with a concentration of 7–14 wt%. Concerning the decorations, it is established that the green colour is due to the presence of copper, while manganese is responsible for the brown colour. These pigments, which represent the typical colours of ‘archaic majolica’, are spread through the glaze homogeneously, apart from one case in which there is clear evidence of manganese oxide crystals.     

FIRING ANALYSIS OF SOUTH-EASTERN MISSOURI INDIAN POTTERY USING IRON MÖSSBAUER SPECTROSCOPY*

The Mössbauer spectra of prehistoric pottery and clay from the Malden Plain of south-eastern Missouri, USA, were examined. The pottery dates from AD 500 to 1400. The earlier sherds were tempered with sand and the later ones with shell. The sherds and clay contain a mixture of illite, smectite, and kaolinite. Most samples of clay and sherds contained both ferric and ferrous species. The spectral parameters for the ferric species were %DLE_Q～0. 7—1.1 mms^-1 and δ～0.0–0.3 mms^-1 for the ferrous species, ΔE_Q～2.1–2.7mms^-1 and δ～0.7–1.0mms^-1. The ferric to ferrous ratio is more accurately determined from the spectra than from consideration of the colour or the firing core of the sherds, which are not always related to the iron species ratio. Differences among sherds in the ferrous ΔE_Q can be related to original temperature of heating but with low precision.