Early development of Jingdezhen ceramic glazes

Major types of ceramics produced in the history of Jingdezhen, from the Tang green glaze stoneware, through the Five Dynasties white ware, the Song dynasty bluish-white ware to the Yuan and Ming dynasties blue-and-white ware were analysed for their glaze chemistries to reveal, chemically, how the glazes of different periods in Jingdezhen evolved. Possible early period glaze recipes are proposed. Important events in the course of the technological development of Jingdezhen ceramic, such as the first use of limestone as a glaze flux, and how they may have impacted the way Jingdezhen ceramic technology advanced, are discussed.     

The Earliest High‐Fired Glazed Ceramic in China: Evidence from a Glazed Ceramic Sample from the Lajia Site,Qinghai Province

In the Majiayao cultural stratum of the Lajia site in Minhe County, Qinghai Province, much earthenware of rich variety and strong character has been found, among which the most special item is a suspected glazed white ceramic fragment. This study investigates this ceramic sherd and many other overfired objects. Energy‐dispersive X‐ray fluorescence spectroscopy, scanning electron microscopy – energy‐dispersive X‐ray spectroscopy, X‐ray diffraction and thermodilatometry were employed to analyse the composition, microstructure, phase composition and firing temperature of the white ceramic. In addition to large condensed glaze droplets, the white ceramic showed a thin and uneven glaze layer, which might represent the earliest results of the exploration of glaze‐making technology by Lajia inhabitants, and provide a new perspective on the study of the origin of Chinese proto‐porcelains.     

Compositional and Microstructural Study of KoryŎ Celadon and Whiteware Excavated from SŎRi Kiln in Kyŏnggi Province

An extensive study of the composition and microstructure of celadon and whiteware sherds excavated at Sori, one of the most important sites that were active during the founding stage of the stoneware and porcelain industry in Korea, was carried out. The analysed sherds were organized according to four different levels of the excavation and four different styles of haemurigup foot rim. Principal component analysis of the chemical compositions of the sherds revealed slight differences in their body and glaze compositions between the levels of excavation. Porcelain stone with high silica and low aluminium contents was generally used as the body material and wood ash as the chief flux in the glaze. Over the period of operation, the aluminium content in the bodies of the ceramics decreased and the P₂O₅ content in the glazes increased. Glazed bodies were fired in a single step, in contrast to the two‐step method used in later ceramic production. Firing conditions were adjusted to produce vitrification of the glazes, which meant that vitrification of the ceramic bodies occurred to varying extents, mostly determined by the relative contents of flux in the body and the glaze.     

New Insights into the Calcium Flux Used in Ancient Longquan and Yue Kilns Based on Strontium Isotopic Compositions

The glazes of seven types of greenware produced in the Yue and Longquan kilns between the Tang dynasty and the Ming dynasty (ad 618–1644) were studied for their strontium isotopic compositions and bulk chemical compositions. The aim was to identify the raw materials used as the calcium fluxes in the glaze recipes and whether the raw materials changed over time, particularly before and after the Southern Song dynasty (ad 1127–1279). From this work, botanic ash has been identified as the raw material used as the calcium flux in all the seven glaze types studied, and some related ceramic historical issues are also 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.     

GLAZED CERAMIC MANUFACTURING IN SOUTHERN TUSCANY (ITALY): EVIDENCE OF TECHNOLOGICAL CONTINUITY THROUGHOUT THE MEDIEVAL PERIOD (10TH–14TH CENTURIES)*

Archaeometric investigation allowed the characterization of two important classes of ceramics: ‘vetrina sparsa’ and ‘invetriata grezza’. Their archaeological peculiarity makes them particularly suited for tracing the evolution of glaze manufacturing in southern Tuscany throughout the medieval period (10th–14th centuries). These ceramics were found in different sites of historical importance, and also from a mining perspective. Local copper, lead, zinc and iron mineralizations supported the growth of several settlements in the vicinity of the mines. The many castles and different archaeological finds (ceramics, glazed ceramic, slag etc.) attest to the intense mineral exploitation of the area from at least the first millennium bc up to the modern period. In light of these geological and archaeological characteristics, archaeometric investigation was intended to provide insight into ancient technical knowledge of ceramic glazing and to determine the source area for raw materials in the medieval period (10th–14th centuries). Ceramic bodies were analysed through OM, XRDp, SEM–EDS and XRF, while coatings were investigated through SEM–EDS. Mineralogical, petrographic and chemical analyses revealed slightly different preparation and firing processes for the two classes of ceramics. These data suggest the continuity through the centuries of the ‘vetrina sparsa’ and ‘invetriata grezza’ production technology. The mineralogical phases, such as monazite, xenotime, zircon, barite, Ti oxide, ilmenite, titanite, tourmaline and ilvaite, and the lithic (intrusive and volcanic) fragments detected within the ceramic bodies suggest a source area in the vicinity of the Campiglia mining district. Lastly, the presence of Cu–Zn–Pb (Ag) and Fe sulphide mineralizations (materials used to produce glaze) in the area supports the hypothesis of local manufacture.     

The technology and production of glazed ceramics from Middle Islamic Jerash,Jordan

Jerash in northern Jordan was, despite a focus on its classical heritage, also active in the Middle Islamic period, but little is known about actual developments during this period. This study represents the first study on the Middle Islamic glazed pottery from the site using scanning electron microscopy energy‐dispersive spectrometry (SEM‐EDS) and thin‐section petrography. The results show that two production traditions existed, each with different provenances. The local production is characterized by a non‐calcareous ceramic body and the use of a high‐lead glaze coloured with iron and copper oxides, whereas the turquoise‐glazed samples, likely imported from Mesopotamia, have a calcareous ceramic body and alkali or alkali‐lead glaze.     

FAIENCE: AN INVESTIGATION OF THE MICROSTRUCTURES ASSOCIATED WITH THE DIFFERENT METHODS OF GLAZING

The microstructures of faience, produced in the laboratory by the direct application of the glazing mixture (both in the raw state and in the form of prefired and ground frit) and by the efflorescence and cementation glazing methods, have been studied in polished sections in the scanning electron microscope (SEM). The microstructures observed were defined in terms of (1) thickness of the surface glaze layer, (2) thickness of the glaze-core interaction layer, (3) nature of the boundary between the interaction layer and the core and (4) extent of any interstitial glass phase within the quartz core. These parameters provide the basis for distinguishing between faience made by the three principal methods of glazing used in antiquity. Hence the method used to glaze an ancient faience object can be inferred from its microstructure as observed in polished section in the SEM.     

THE TECHNOLOGY OF PRODUCTION OF SASANIAN GLAZED POTTERY FROM VEH ARDAŠ?R (CENTRAL IRAQ)

Scanning electron microscopy coupled with an energy dispersive X‐ray detector (SEM‐EDS) has been used to study samples of Sasanian glazed pottery. Analysis of ceramic bodies revealed a general homogeneity in composition among the studied samples and the use of calcareous clay for their manufacture. Glazes are typically alkaline in composition, with sodium and potassium oxide contents between 8 and 13%, and between 3 and 5%, respectively; calcium and magnesium oxide contents are between 7 and 10%, and between 3 and 5%, respectively. These data suggest the use of plant ash together with a silica source for glaze production. Coating thickness is highly variable among different samples, from some 400 up to 1200 µm, but it is generally uniform when a single sample is concerned. Glazes are mostly coloured blue or blue‐green; copper and iron are the colouring agents detected; abundance of bubbles, silicate crystals and relics of unmelted material are responsible for their generally opaque appearance, together with the presence of weathering products. The characteristics of the body to glaze contact zone, together with the widespread presence of bubbles, would not rule out production by a single firing process. A few samples feature a peculiar gritty coating on one side of their surface; SEM images show that they are actually partially vitrified, and EDS data denote a rather heterogeneous composition. It seems possible that they result from mixing clay together with the frit used for glaze development.     

INCISED SLIPWARE PRODUCTION AT CASTELFIORENTINO (FLORENCE): THE ‘VIA BERTINI’ SITE (15TH–17TH CENTURIES)*

This study deals with the physical–chemical and mineralogical–petrographic investigations (OM, SEM–EDS, EPMA, ICP, XRpD, Mössbauer and IR) conducted on first‐ and second‐firing wasters belonging to two types of incised slipware (sgraffito), manufactured at Castelfiorentino between the late 15th and the early 17th centuries. Raw materials, colouring agents and firing products were analysed in order to establish the production technology of the ceramic coatings, by means of detailed microtextural and chemical investigations. The pottery underwent two firing processes: the firing of the white slip‐coated ceramic body and a further firing after application of the glaze. The homogeneity of the raw materials, white slip and glaze is remarkable, and demonstrates the use of well‐established recipes with a constant supply of raw materials from the same places. Highly efficient kiln management during both firings is revealed by body–glaze interface reactions.     

安吉上马山汉代江东类型原始瓷工艺研究

安吉上马山汉代土墩墓墓群出土众多江东类型高温釉原始瓷器,SEM-EDS (能谱-扫描电镜)分析显示,其中部分样品的胎体外表面施有含钾、铁含量较高的红色层,可能是化妆土的前身,并且在红色层之上还局部施有钙釉。经过与江西地区早商以来一些遗物在外貌以及陶衣成分上的对比,发现上马山的这些原始瓷也许在源流上与江西地区的早期窑业有关。而当东汉末年,越地传统单层高温钙釉器物逐渐兴起,并发展成为最早的成熟青瓷,这种化妆土技术便于越地消失了。     

Pottery technology in the Tang dynasty (ninth century ad): archaeometric analyses of a Gongyi sherd found at Siraf,Iran

In 1969–70, a single Tang dynasty blue‐spotted Gongyi sherd was found at Siraf, Iran, the main trading port on the Persian Gulf in the early Islamic period. This is the only known example of Chinese blue‐and‐white ware, whether low‐ or high‐fired, found in the Middle East from such an early date. The sherd provides direct archaeological evidence for the Indian Ocean trade between China and the Middle East in the ninth century ad . The body paste, clear glaze and blue glaze or pigment were analysed by thin‐section petrography, scanning electron microscopy with energy‐dispersive X‐ray spectrometry (SEM‐EDX) and X‐ray fluorescence (XRF). The technological analysis reveals the different steps of the chaîne opératoire: clay mixing, slip and glaze application, and decoration with the cobalt blue glaze before high‐temperature firing. These steps are characteristic of Tang stoneware production at Gongyi in Henan province, China. The use of cobalt blue pigment as part of a simple spotted decoration scheme on the Gongyi sherd, and its find context within the Middle East, provides evidence for the complex interplay and influence occurring between Chinese and Middle East ceramic industries at this time. Closely comparable examples of contemporary low‐fired earthenware ceramics with cobalt blue decoration on a white tin glaze manufactured within the Middle East also occur within the same assemblage from Siraf.     

用微探针型EDXRF技术研究南宋官窑瓷片的化学组成及其含义

本文报道了用ENGLE-Ⅱ微探针能量色散型X荧光光谱（EDXRF）技术测定一批青瓷残片中的16种元素氧化物的含量．其残片来自浙江杭州地区南宋的郊坛窑和老虎洞窑。由主量元素判别方程。值表明,郊坛和老虎洞青釉瓷均属官窑制品,与龙泉民窑产品有很大差别。从主成分统计分析看出．郊坛下官窑与老虎洞官窑的瓷釉成分有明显不同,但其胎质成分的分布却有部分的重叠。这显示两类同属官窑的制品,其釉料可有不同的矿物组合。但胎料有时会交流使用。从釉层、中间层、和胎层的Al2O3和CaO的含量变化数据表明,郊坛下官窑和老虎洞官窑的青瓷制品有厚度分别为120-140um和230-240μm的中间层,反映出烧造工艺上有一定的差别。化学成分鉴定证实了考古工作者认为老虎洞窑实为史书记载的修内司官窑的观点．     

关于青花起源的思考

关于青花的起源,长期来一直有中国起源说和外来技术影响说两种意见。本文着重从低温釉陶生产技术源流和对青料的使用出发,论证了最早出现在巩县窑的唐青花瓷器,只是北魏以来低温釉陶生产技术在新条件下的新产物。认定唐青花的出现是外来绘画理论和绘画技术影响中国艺坛的结果。     

故宫养心殿燕喜堂古建筑琉璃构件的釉面损毁研究

故宫建筑琉璃构件面临最主要的病变是琉璃釉层的大面积脱落,以养心殿燕喜堂最为典型的琉璃筒瓦为研究对象,分析釉层和胎体的成分、形貌以及热性能等,同时进行不同条件下的模拟循环试验发现:环境温湿度变化剧烈,会引起琉璃样品的釉层脱落,其中样品釉层越厚、胎釉与胎体的热扩散性能和热膨胀性能差异越大,样品釉层脱落的速率会越快。分析原因主要在于琉璃样品从高温急剧降到低温等循环过程发生的“淬火”,样品从高温下降至冷冻室冰水混合物中表面釉层的温度下降速率相对最大,这种温度的急剧变化会引起釉层张应力以及胎釉界面热应力的分布不均,釉层脱落破坏最为严重。对比琉璃样品发生破坏时的模拟实验条件和实际环境条件,与夏季的高温/暴雨最为相似,推测可能成为破坏古建筑琉璃釉面脱落的最主要因素之一。研究成果可为后期文物保护和修复方案的提出提供科学依据。     

甘肃张家川马家塬战国墓地M4出土料珠研究

甘肃马家塬墓地是战国晚期至秦初的西戎墓地,本研究以该墓地M4出土的料珠为研究对象,以期通过分析其成分和结构特征,讨论其工艺特征,以丰富对战国时期费昂斯的相关认识。研究使用扫描电子显微镜-能谱和激光拉曼光谱仪,分析结果显示料珠为费昂斯制品,其釉层玻璃化程度很高,经历腐蚀后熔剂流失严重,明显区别于西周时期的费昂斯制品。同时确定釉层中的一些高锡颗粒物为SnO_2,表明当时在釉层制作中加入锡石或锡粉末。该费昂斯制品应采取了直接施釉或包埋施釉工艺。研究结果可为我国费昂斯发展历程演变提供信息。     

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.     

汝州东沟窑金元时期青瓷与钧瓷原料和工艺特征的比较研究

金元时期在豫西中部地区多个窑址同时生产青瓷和钧瓷,发掘于2005年的汝州东沟窑遗址即是该类窑址典型代表之一。为系统了解东沟窑青瓷和钧瓷的胎釉元素组成特征和工艺特点、揭示两类瓷器各自随时代变化的规律,本项研究采用EDXRF和OM对东沟窑遗址出土且地层明确的43件金、元时期青瓷与钧瓷标本胎、釉化学组成和工艺性能进行测试分析,探讨了胎、釉的原料配比、釉层厚度和胎釉反应层厚度等工艺特征随时代和标本类型的变化规律。研究结果表明:东沟窑同时期青瓷和钧瓷胎体元素组成较接近,而两者釉的元素组成差异明显,金元钧瓷釉的SiO2/Al2O3摩尔比值都明显高于同时代青瓷的相应比值,呈现钧瓷釉典型的高硅低铝组成特征。从金代到元代,东沟窑青瓷和钧瓷釉都呈现从钙釉向钙-碱釉的转变。本项研究还观察到金元钧瓷的釉层和反应层厚度均高于同时代的青瓷;而从金过渡到元,两类瓷片的釉层和反应层厚度均趋厚。本项研究对揭示金元时期豫西中部地区青瓷和钧瓷间的传承和演化关系提供了有意义的科技数据。     

孔雀蓝釉技术源流考辨

孔雀蓝釉是中国陶瓷低温釉体系中重要的环节,正是由于孔雀蓝釉的配制,我国低温釉出现了以氧化钾作为熔剂的技术手段,为后来景德镇釉上彩的彩料配制奠定了技术基础。孔雀蓝釉的技术来源尚没有清楚的认识,学者大多推测中国孔雀蓝釉的生产受到了伊斯兰陶孔雀蓝釉的影响。但现有对金元时期我国孔雀蓝釉的检测表明有多种配方共存的情况,这一现象说明当时孔雀蓝釉的生产并没有统一技术。笔者通过对孔雀蓝釉出土文物的时间与产地特征,以及对琉璃瓦生产工艺演变的考察,认为我国孔雀蓝釉是在低温铅釉琉璃的助熔剂"黄丹"的制作工艺演变过程中增加硝形成的,到元代中期以后配方探索才逐渐完成,形成了以硝为主要助熔剂的制作工艺。     

“南澳Ⅰ号”出水陶瓷器脱盐技术对比研究

为了对“南澳Ⅰ号”明代沉船出水的大量陶瓷类文物进行安全高效的脱盐保护处理,选取“南澳Ⅰ号”出水的3种不同窑系的陶瓷文物作为研究对象,对其胎体理化性能进行分析检测与对比,并在常温静水浸泡、加热静水浸泡、超声波与加热-超声波4种方法11种不同技术参数下分别进行脱盐实验,并作对比研究。研究发现,加热与超声波技术相比常温浸泡法可以大幅度提高脱盐的速率,但是随着温度的继续升高与超声波频率的增加,脱盐速率增加幅度不大。实验中发现超声波对比较脆弱的陶瓷文物的釉面与胎体会产生一定影响。在对比实验基础上提出了3种不同窑系的陶瓷文物相应的最佳脱盐参数,以期为安全高效地完成“南澳Ⅰ号”出水的2万多件陶瓷器的保护脱盐提供研究支持,并为其他沉船陶瓷器保护提供借鉴。