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Study on the elemental features of ancient Chinese white porcelain at Jingdezhen by INAA
Nuclear Instruments and Methods in Physics Research B 267 (2009) 821–824
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Nuclear Instruments and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb
Study on the elemental features of ancient Chinese white porcelain at Jingdezhen by INAA Guoxi Xie a,b, Songlin Feng a,*, Xiangqian Feng a, Yongqiang Li c, Hongye Han c, Yanqing Wang a, Jihao Zhu a, Lingtong Yan a, Li Li a a
Institute of High Energy Physics, The Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049, China Graduated University of Chinese Academy of Sciences, Beijing 100049, China c Beijing Institute of Cultural Relics, Beijing 100009, China b
a r t i c l e
i n f o
Article history: Received 9 May 2008 Received in revised form 16 December 2008 Available online 3 January 2009 PACS: 32.30.Rj 82.80.Ej 91.65.Nd Keywords: Ancient Chinese white porcelain INAA Nuclear technology
a b s t r a c t Shards of ancient Chinese white porcelain, which were excavated at Maojiawan in the city of Beijing, were analyzed by instrumental neutron activation analysis (INAA). These shards were fired in the period between the Yuan (AD 1271–1368) and Ming (AD 1368–1644) dynasties at Jingdezhen in southern China. According to the analytical results, different raw materials were used for making porcelain body in this period. Fe and Na are the characteristic elements which can be used for identifying the specific date of these porcelains. Furthermore, shards of Hongwu era (AD 1368–1398), Yongle-Xuande era (AD 1403– 1435) and Chenghua-Zhengde era (AD 1465–1561) of the Ming dynasty can be clearly distinguished by their elemental body composition. The temporal chemical variation in the porcelain body of these eras is observed. The elemental body composition of Zhengde-Tianshun era (AD 1436–1464) is mainly similar to that of the Hongwu and Yongle-Xuande eras. The temporal chemical feature of Zhengtong-Tianshun era was not found. Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction Ancient Chinese white porcelain began to be fired in the Late Northern dynasty (AD 386–581) and developed in the period between the Sui (AD 581–618) and Tang dynasties (AD 618–907). After the Song dynasty (AD 960–1279), it became one of the most important porcelains in China [1,2]. It is famous for its pure white body, transparent glaze and skillful carved patterns [3]. Although the most famous ancient Chinese white porcelain was produced at Xing kiln, Ding kiln and Jingxing kiln in northern China in the Song dynasty (AD 960–1279), the mass of ancient Chinese white porcelains were also produced at Jingdezhen in southern China from the Yuan (AD 1271–1368) to the Ming dynasties (AD 1368– 1644). For example, the famous ancient white porcelain named ‘‘egg-white porcelain” was fired at Jingdezhen in the Yuan dynasty. In September 2005, an enormous porcelain shard pit was found at Maojiawan, in the city of Beijing, China. Hundreds of ancient Chinese white porcelain shards were excavated from this pit. The dates and provenances of these shards were clearly identified by archaeologists, based on their exterior characteristics. Most of
* Corresponding author. E-mail address: [email protected] (S. Feng). 0168-583X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2008.12.020
them were fired at private-kilns in Jingdezhen in the period between the Yuan and Ming dynasties [4]. They can be used not only for studying the manufacturing technology, but also as standard specimens to specify the date or provenance of other porcelain. At present, the customary method for dating ancient Chinese porcelain depends on the fact that the shapes and decorations change in the different dynasties [5]. However, it is difficult to correctly identify the specific date of some kinds of ancient Chinese porcelain by only using their visual characteristics [6], because the visual features of these porcelains were vary only a little or they were greatly imitated in later dynasties. It is well known that the contents of major, minor and trace elements of a porcelain body and glaze are dependent on its raw material and manufacturing technology [7]. They can be used for tracing the porcelain’s age and its provenance [8–10]. In this article, we try to find the elemental features of ancient Chinese white porcelains which were fired at the Jingdezhen private kiln from the Yuan to the Ming dynasties based on instrumental neutron activation analysis (INAA) experiments. INAA is an efficient method for elemental analysis since it provides high sensitivity, blank-free and multi-elemental analysis. It has been widely used for determining the elemental composition of ancient porcelain [11–13].
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G. Xie et al. / Nuclear Instruments and Methods in Physics Research B 267 (2009) 821–824
2. Experimental
Table 2 Contents of 19 elements in the certified reference material GBW07103 by INAA.
2.1. Samples
Element (/ppm)
Experiment value (Mean ± Std.)
Reference value (Mean ± Std.)
La Sm Na U Ce Nd Eu Tb Yb Lu Hf Ta Th Sc Fe Co Rb Cs Ba
58 ± 2 10.3 ± 0.3 20,500 ± 595 20.2 ± 1.0 106 ± 4 45 ± 5 0.83 ± 0.10 1.44 ± 0.22 7.28 ± 0.38 1.01 ± 0.09 6.3 ± 0.4 6.4 ± 0.3 48 ± 1 5.8 ± 0.1 14,900 ± 600 3.0 ± 0.3 451 ± 14 31.8 ± 0.4 348 ± 57
54 ± 4 9.7 ± 0.8 23,224 ± 600 18.8 ± 1.4 108 ± 7 47 ± 4 0.85 ± 0.07 1.65 ± 0.09 7.4 ± 0.5 1.15 ± 0.09 6.3 ± 0.8 7.2 ± 0.7 54 ± 3 6.1 ± 0.4 14,900 ± 400 3.4 ± 0.7 466 ± 17 38.4 ± 1.2 343 ± 29
One hundred and sixteen typical shards of ancient Chinese white porcelain which were excavated from the shard pit of Maojiawan were selected. The dates and provenances of these shards were well identified. All of them were fired at private-kilns in Jingdezhen, China. Sixteen shards were fired in the Yuan dynasty. They were the famous ancient Chinese white porcelain which was named ‘‘egg-white”. Other shards were fired in the Ming dynasty. The Ming dynasty lasted 276 years and had 17 emperors. The manufacturing technology of ancient porcelain could be changed in different periods. According to their exterior characteristics, shards of Ming dynasty were classified into four groups by archaeologists of Beijing Institute of Cultural Relics. These four groups are Hongwu era (AD 1368–1398), Yongle-Xuande era (AD 1403–1435), Zhengtong-Tianshun era (AD 1436–1464), and Chenghua-Zhengde era (AD 1465–1521) [14]. The detailed information of the experimental samples is listed in Table 1. 2.2. INAA experiment A sample of dimensions 30 mm 10 mm was cut from each shard. After abrading the glaze away, the pure bodies were washed in an ultrasonic bath with deionized water three times, then dried at 105 °C for 8 h. After these steps, the pure body was ground into a powder of maximum granular diameter less than 74 lm with an agate mortar. About 30 mg of each powder sample was wrapped in aluminum foil of 99.999% purity. The wrapped samples were placed in the reactor of the Chinese Institute of Atomic Energy together with calibration standards and a quality control standard. They were irradiated for 8 h in a neutron flux of 6.9 1013 n cm 2 s 1. The calibration standards are single or multi-element solutions [15] and the quality control standard is the Chinese national certified reference material of rock (GBW07103) [16]. The c energy spectrum of each sample was measured by a HPGe detector, which is connected to a multi-channel analyzer, and processing with the Span 5.1 software package. The first measurement was made after cooling for 5–7 days with a live time of 2000 s. The second measurement was made after 18–20 days with a live time of 3000 s. Under these conditions, 19 elements, La, Sm, Na, U, Ce, Nd, Eu, Tb, Yb, Lu, Hf, Ta, Th, Sc, Fe, Co, Rb, Cs, Ba, were determined. The validation of the analytical method applied in these works was carried out by analysis of GBW07103. The results show that the experimental values are in good agreement with the certified ones (See Table 2). 3. Results and discussion The average values of each element in porcelain body of the Yuan and Ming dynasties are shown in Table 3. Values of Na, Fe, U, Yb, Ta, Rb and Cs in porcelain body of the Yuan dynasty are much higher than those of the Ming dynasty. The value of Ba in porcelain body of the Yuan dynasty is also distinctively different
from that of the Ming dynasty. It obviously shows that the elemental composition in porcelain body of the Yuan dynasty is different from that of the Ming dynasty. Fe greatly influences the porcelain body color since it can produce gray or black porcelain body in a reducing atmosphere [17]. The less Fe in porcelain body, the purer white the porcelain body appears. The average value of Fe2O3 in porcelain bodies of the Yuan dynasty is 1.39 ± 0.33%, while that of the Ming dynasty is 0.86 ± 0.19%. It shows that different raw materials for making porcelain body were used in the Yuan and Ming dynasties. This analytical result is in accordance with the history of manufacturing technology of Jingdezhen porcelain-producing field [18]. The scatterplot of Na and Fe is displayed in Fig. 1. All samples are clearly located on two regions of the plot. Samples of the Yuan dynasty are concentrated in the upper right region while samples of the Ming dynasty are concentrated in the lower left region. We can therefore use the concentrations of Fe and Na to classify these ancient Chinese white porcelains into the Yuan and Ming dynasties. Fe and Na are the characteristic elements of ancient Chinese white porcelain which were fired at Jingdezhen in the Yuan and Ming dynasties. The average values of each element in porcelain body of different eras of the Ming dynasty are shown in Table 4. Although the elemental composition is slightly different among Hongwu era, Yongle-Xuande era, Zhengtong-Tianshun era and ChenghuaZhengde era, they can not be completely distinguished by using the contents of any two or three elements. It is necessary to transform the original experimental data to separate them by mathematical methods. Principle component analysis (PCA) and the Fisher linear discriminant have been widely used in archaeology [19–21]. The main objective of PCA is to reduce the dimension of the observations through a linear transformation. Low dimensional linear combinations are often easier to interpret and serve as an intermediate step in a more complex data analysis. The objective
Table 1 The detailed information of experimental samples excavated from the sherd pit of Maojiawan in the city of Beijing, China.
Ming
Groups
Number
Age
Provenance
Yuan Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
16 11 20 49 20
Yuan dynasty (AD 1271–1368) Hongwu era of Ming dynasty (AD 1368–1398) Yongle to Xuande era of Ming dynasty (AD 1403–1435) Zhengtong to Tianshun era of Ming dynasty (AD 1436–1464) Chenghua to Zhengde era of Ming dynasty (AD 1465–1521)
Jingdezhen Jingdezhen Jingdezhen Jingdezhen Jingdezhen
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G. Xie et al. / Nuclear Instruments and Methods in Physics Research B 267 (2009) 821–824 Table 3 The average elemental values of each element in porcelain bodies of the Yuan and Ming dynasties. Groups
Number
Na2O (%)
Fe2O3 (%)
La (ppm)
Sm (ppm)
U (ppm)
Ce (ppm)
Yuan Ming
16 100
1.73 ± 0.33 0.68 ± 0.30
1.39 ± 0.33 0.86 ± 0.19
12.7 ± 3.8 14.7 ± 8.2
3.67 ± 0.81 3.68 ± 1.29
9.93 ± 2.86 5.21 ± 1.22
22.9 ± 4.9 20.0 ± 7.3
Yuan Ming
Nd (ppm) 16.9 ± 5.3 13.3 ± 6.6
Eu (ppm) 0.53 ± 0.19 0.58 ± 0.18
Tb (ppm) 0.74 ± 0.16 0.56 ± 0.16
Yb (ppm) 3.01 ± 0.22 1.51 ± 0.52
Lu (ppm) 0.24 ± 0.03 0.16 ± 0.03
Hf (ppm) 3.58 ± 0.30 3.27 ± 0.30
Ta (ppm) 9.07 ± 1.67 3.72 ± 0.23
Yuan Ming
Th (ppm) 9.7 ± 2.7 11.0 ± 4.2
Sc (ppm) 3.05 ± 0.88 3.27 ± 0.47
Co (ppm) 3.42 ± 1.85 3.71 ± 3.75
Rb (ppm) 553 ± 110 279 ± 43
Cs (ppm) 67.7 ± 21.7 30.9 ± 5.8
Ba (ppm) 156 ± 37 204 ± 46
Fig. 1. Scatterplot of Na and Fe in bodies of ancient Chinese white porcelain of the Yuan and Ming dynasties.
Fig. 2. The analytical result of PCA on all samples.
of using the Fisher linear discriminant is to build classification functions, and then classify an unknown object into previously defined categories. Fisher suggested finding a linear combination which maximizes the ratio of the between-group sum of squares to the within-group sum of squares to build classification functions [22]. Sometimes, this can be used to separate groups which were overlapping using PCA methods.
The result of PCA on all samples is shown in Fig. 2. Samples of the Yuan dynasty are located on the left region while samples of Hongwu era, Yongle-Xuande era, Zhengtong-Tianshun era and Chenghua-Zhengde era are distributed on the right region. This distribution is the same as the scatterplot of Na and Fe (Fig. 1). Samples of Hongwu era, Yongle-Xuande era, Zhengtong-Tianshun
Table 4 The average elemental values of each element in porcelain bodies of different eras of the Ming dynasty. Groups
Number
Na2O (%)
Fe2O3 (%)
La (ppm)
Sm (ppm)
U (ppm)
Ce (ppm)
Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
11 20 20 49
0.20 ± 0.24 0.74 ± 0.29 0.65 ± 0.22 0.78 ± 0.25
1.04 ± 0.09 0.75 ± 0.09 1.05 ± 0.22 0.80 ± 0.13
29.7 ± 9.2 11.4 ± 4.4 20.8 ± 7.2 10.1 ± 3.7
6.05 ± 1.21 3.59 ± 0.98 4.37 ± 0.72 2.90 ± 0.67
6.03 ± 0.67 5.36 ± 1.81 5.78 ± 0.91 4.74 ± 0.93
29.9 ± 4.0 16.9 ± 5.4 25.9 ± 6.5 16.6 ± 5.0
Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
Nd (ppm) 26.1 ± 6.5 11.7 ± 4.5 16.9 ± 4.6 9.7 ± 2.6
Eu (ppm) 0.90 ± 0.27 0.49 ± 0.11 0.65 ± 0.14 0.52 ± 0.10
Tb (ppm) 0.90 ± 0.16 0.53 ± 0.11 0.59 ± 0.10 0.48 ± 0.08
Yb (ppm) 2.55 ± 0.35 1.60 ± 0.36 1.75 ± 0.32 1.15 ± 0.15
Lu (ppm) 0.22 ± 0.04 0.14 ± 0.02 0.16 ± 0.03 0.15 ± 0.02
Hf (ppm) 3.37 ± 0.28 3.20 ± 0.20 2.98 ± 0.27 3.39 ± 0.26
Ta (ppm) 5.85 ± 0.71 3.36 ± 1.32 3.75 ± 1.24 3.38 ± 0.71
Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
Th (ppm) 16.7 ± 1.7 11.0 ± 4.3 12.9 ± 2.5 8.9 ± 3.4
Sc (ppm) 3.84 ± 0.70 2.99 ± 0.20 3.48 ± 0.55 3.17 ± 0.28
Co (ppm) 6.01 ± 1.76 1.67 ± 0.58 6.35 ± 3.08 2.94 ± 4.25
Rb (ppm) 325 ± 23 282 ± 57 269 ± 47 271 ± 31
Cs (ppm) 29.6 ± 10.6 29.5 ± 4.5 31.9 ± 6.9 31.4 ± 4.3
Ba (ppm) 137 ± 26 201 ± 48 192 ± 34 224 ± 36
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elemental difference between the Yuan and Ming dynasties is larger than the difference among Hongwu, Yongle-Xuande, Zhengtong-Tianshun and Chenghua-Zhengde eras of the Ming dynasty. The elemental compositions in porcelain body of Hongwu era, Yongle-Xuande era and Chenghua-Zhengde era are slightly different, indicating temporal chemical variation. However, the elemental composition in porcelain body of Zhengtong-Tianshun era is mainly similar with that of Hongwu and Yongle eras and no characteristic discriminating chemical feature was found for the Zhengtong-Tianshun era. Acknowledgements The authors greatly appreciate the financial support from the Knowledge Innovative Program of Chinese Academy of Sciences (No. KJCX3.SYW.N12), The Youth Innovative Foundation of Institute of High Physics of Chinese Academy of Sciences (No. 542007IHEPZZBS546100), Natural Science Foundation of Beijing City (No. 1082009) and National Natural Science Foundation of China (Nos. 10705032 and 10675143). References
Fig. 3. The analytical result of Fisher linear discriminant on all samples.
era and Chenghua-Zhengde era are not well separated. This means that the elemental difference between the Yuan and Ming dynasties is larger than the difference among Hongwu era, YongleXuande era, Zhengtong-Tianshun era and Chenghua-Zhengde era of the Ming dynasty. The raw materials for making porcelain bodies were changed in the period between the Yuan and Ming dynasties. Using the Fisher linear discriminant to interpret the experimental data, the result is shown in Fig. 3. Samples of the Yuan dynasty are still separated from that of the Ming dynasty. Samples of Hongwu era, Yongle-Xuande era and Chenghua-Zhengde era are separately distributed on the left region of the plot. It shows that these groups can be clearly distinguished by their elemental body composition so the temporal chemical variation among Hongwu era, Yongle-Xuande era and Chenghua-Zhengde era is clearly observed. Samples of Zhengtong-Tianshun era are overlapping with the samples of Hongwu era and Yongle-Xuande era. A characteristic discriminating chemical feature in porcelain bodies of ZhengtongTianshun era is not found. 4. Conclusions INAA has been used to analyze the elemental composition in body of ancient Chinese white porcelain excavated from Maojiawan. According to the experimental data, the elemental composition is different in porcelain body of the Yuan and Ming dynasties. Fe and Na are the characteristic elements which can be used to classify shards into these two dynasties. It is obviously shown that different raw materials for making porcelain body were used in the period between the Yuan and Ming dynasties. The results from PCA and the Fisher linear discriminant show that the
[1] The Chinese Ceramic Society, The History of Chinese Pottery and Porcelain, Cultural of Relics Publishing House, Beijing, 1982, p. 181. [2] Fukang Zhang, Scientific Technology of Ancient Chinese Porcelain, Shanghai People’s Fine Arts Publishing House, Shanghai, 2000. p. 67. [3] Jiazhi Li, The History of Chinese Scientific Technology Ceramic Volume, Science Publishing House, Beijing, 1998. p. 143. [4] Beijing Institute of Cultural Relics, Excavation Report on a Ming Period Porcelain Burial at Maojiawan, Science Publishing House, Beijing, 2007, p. 126. [5] Huibing Li, The Basic Knowledge About Identifying Ancient Chinese Porcelain, Forbidden City Publishing House, Beijing, 2001. p. 100. [6] Naizhang Zheng et al., Chemical composition analytical methods being instruments on the identifications and studies of ancient ceramics by instruments, China Ceramic 43 (5) (2007) 52. [7] Songlin Feng et al., Application of nuclear analysis techniques in ancient Chinese porcelain, Nucl. Phys. Rev. 22 (1) (2005) 13. [8] Dongyu Fan et al., Study of elements in Yue Kiln ancient celadon by SRXRF and factor analysis, Nucl. Techn. 25 (10) (2005) 136. [9] Xiangqian Feng et al., Ding and study of discriminating criteria, Nucl. Techn. 25 (10) (2005) 827. [10] H.S. Cheng et al., The non-destructive identification of early Chinese porcelain by PIXE, Nucl. Instr. and Meth. B 219–220 (2004) 16. [11] Guoxi Xie et al., Study on ancient Chinese imitated GE ware by INAA and WDXRF, Nucl. Instr. and Meth. B 264 (2007) 103. [12] Guoxi Xie et al., Trace element analysis for ancient Chinese celadon porcelain excavated from the Maojiawan site, J. Chin. Ceramic Soc. 35 (9) (2007) 1222. [13] Guoxia Li et al., Application of neutron activation analysis in study of ancient ceramics, Nucl. Phys. Rev. 17 (4) (2000) 248. [14] Beijing Institute of Cultural Relics, Excavation Report on a Ming Period Porcelain Burial at Maojiawan, Science Publishing House, Beijing, 2007, p. 474. [15] R.R. Greenberg, Accuracy in standards preparation for neutron activation analysis, J. Radioanal. Nucl. Chem. 179 (1) (1994) 131. [16] List of Reference Materials, China Measurement Press, Beijing, 2000, p. 60. [17] Fukang Zhang, Scientific Technology of Ancient Chinese Porcelain, Shanghai People’s Fine Arts Publishing House, Shanghai, 2000. p. 3. [18] Jiazhi Li, The History of Chinese Scientific Technology, Ceramic Volume, Science Publishing House, Beijing, 1998. p. 325. [19] Guoxi Xie et al., Study on the provenance of ancient porcelain excavated in Maojiawan ruin by WDXRF analysis, Nucl. Techn. 30 (4) (2007) 1. [20] Jihao Zhu et al., Study of provenance character on ancient porcelain of Yue Kiln at Silongkou with NAA, J. Radioanal. Nucl. Chem. 272 (3) (2007) 545. [21] D. Zhu et al., PIXE study on the provenance of Chinese ancient porcelain, Nucl. Instr. and Meth. B 249 (2006) 633. [22] W. Härdle, L. Simar, Applied Multivariate Statistical Analysis, Springer, Berlin, 2003. p. 323.
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Nuclear Instruments and Methods in Physics Research B journal homepage: www.elsevier.com/locate/nimb
Study on the elemental features of ancient Chinese white porcelain at Jingdezhen by INAA Guoxi Xie a,b, Songlin Feng a,*, Xiangqian Feng a, Yongqiang Li c, Hongye Han c, Yanqing Wang a, Jihao Zhu a, Lingtong Yan a, Li Li a a
Institute of High Energy Physics, The Chinese Academy of Sciences, 19 Yu Quan Lu, Beijing 100049, China Graduated University of Chinese Academy of Sciences, Beijing 100049, China c Beijing Institute of Cultural Relics, Beijing 100009, China b
a r t i c l e
i n f o
Article history: Received 9 May 2008 Received in revised form 16 December 2008 Available online 3 January 2009 PACS: 32.30.Rj 82.80.Ej 91.65.Nd Keywords: Ancient Chinese white porcelain INAA Nuclear technology
a b s t r a c t Shards of ancient Chinese white porcelain, which were excavated at Maojiawan in the city of Beijing, were analyzed by instrumental neutron activation analysis (INAA). These shards were fired in the period between the Yuan (AD 1271–1368) and Ming (AD 1368–1644) dynasties at Jingdezhen in southern China. According to the analytical results, different raw materials were used for making porcelain body in this period. Fe and Na are the characteristic elements which can be used for identifying the specific date of these porcelains. Furthermore, shards of Hongwu era (AD 1368–1398), Yongle-Xuande era (AD 1403– 1435) and Chenghua-Zhengde era (AD 1465–1561) of the Ming dynasty can be clearly distinguished by their elemental body composition. The temporal chemical variation in the porcelain body of these eras is observed. The elemental body composition of Zhengde-Tianshun era (AD 1436–1464) is mainly similar to that of the Hongwu and Yongle-Xuande eras. The temporal chemical feature of Zhengtong-Tianshun era was not found. Ó 2009 Elsevier B.V. All rights reserved.
1. Introduction Ancient Chinese white porcelain began to be fired in the Late Northern dynasty (AD 386–581) and developed in the period between the Sui (AD 581–618) and Tang dynasties (AD 618–907). After the Song dynasty (AD 960–1279), it became one of the most important porcelains in China [1,2]. It is famous for its pure white body, transparent glaze and skillful carved patterns [3]. Although the most famous ancient Chinese white porcelain was produced at Xing kiln, Ding kiln and Jingxing kiln in northern China in the Song dynasty (AD 960–1279), the mass of ancient Chinese white porcelains were also produced at Jingdezhen in southern China from the Yuan (AD 1271–1368) to the Ming dynasties (AD 1368– 1644). For example, the famous ancient white porcelain named ‘‘egg-white porcelain” was fired at Jingdezhen in the Yuan dynasty. In September 2005, an enormous porcelain shard pit was found at Maojiawan, in the city of Beijing, China. Hundreds of ancient Chinese white porcelain shards were excavated from this pit. The dates and provenances of these shards were clearly identified by archaeologists, based on their exterior characteristics. Most of
* Corresponding author. E-mail address: [email protected] (S. Feng). 0168-583X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.nimb.2008.12.020
them were fired at private-kilns in Jingdezhen in the period between the Yuan and Ming dynasties [4]. They can be used not only for studying the manufacturing technology, but also as standard specimens to specify the date or provenance of other porcelain. At present, the customary method for dating ancient Chinese porcelain depends on the fact that the shapes and decorations change in the different dynasties [5]. However, it is difficult to correctly identify the specific date of some kinds of ancient Chinese porcelain by only using their visual characteristics [6], because the visual features of these porcelains were vary only a little or they were greatly imitated in later dynasties. It is well known that the contents of major, minor and trace elements of a porcelain body and glaze are dependent on its raw material and manufacturing technology [7]. They can be used for tracing the porcelain’s age and its provenance [8–10]. In this article, we try to find the elemental features of ancient Chinese white porcelains which were fired at the Jingdezhen private kiln from the Yuan to the Ming dynasties based on instrumental neutron activation analysis (INAA) experiments. INAA is an efficient method for elemental analysis since it provides high sensitivity, blank-free and multi-elemental analysis. It has been widely used for determining the elemental composition of ancient porcelain [11–13].
822
G. Xie et al. / Nuclear Instruments and Methods in Physics Research B 267 (2009) 821–824
2. Experimental
Table 2 Contents of 19 elements in the certified reference material GBW07103 by INAA.
2.1. Samples
Element (/ppm)
Experiment value (Mean ± Std.)
Reference value (Mean ± Std.)
La Sm Na U Ce Nd Eu Tb Yb Lu Hf Ta Th Sc Fe Co Rb Cs Ba
58 ± 2 10.3 ± 0.3 20,500 ± 595 20.2 ± 1.0 106 ± 4 45 ± 5 0.83 ± 0.10 1.44 ± 0.22 7.28 ± 0.38 1.01 ± 0.09 6.3 ± 0.4 6.4 ± 0.3 48 ± 1 5.8 ± 0.1 14,900 ± 600 3.0 ± 0.3 451 ± 14 31.8 ± 0.4 348 ± 57
54 ± 4 9.7 ± 0.8 23,224 ± 600 18.8 ± 1.4 108 ± 7 47 ± 4 0.85 ± 0.07 1.65 ± 0.09 7.4 ± 0.5 1.15 ± 0.09 6.3 ± 0.8 7.2 ± 0.7 54 ± 3 6.1 ± 0.4 14,900 ± 400 3.4 ± 0.7 466 ± 17 38.4 ± 1.2 343 ± 29
One hundred and sixteen typical shards of ancient Chinese white porcelain which were excavated from the shard pit of Maojiawan were selected. The dates and provenances of these shards were well identified. All of them were fired at private-kilns in Jingdezhen, China. Sixteen shards were fired in the Yuan dynasty. They were the famous ancient Chinese white porcelain which was named ‘‘egg-white”. Other shards were fired in the Ming dynasty. The Ming dynasty lasted 276 years and had 17 emperors. The manufacturing technology of ancient porcelain could be changed in different periods. According to their exterior characteristics, shards of Ming dynasty were classified into four groups by archaeologists of Beijing Institute of Cultural Relics. These four groups are Hongwu era (AD 1368–1398), Yongle-Xuande era (AD 1403–1435), Zhengtong-Tianshun era (AD 1436–1464), and Chenghua-Zhengde era (AD 1465–1521) [14]. The detailed information of the experimental samples is listed in Table 1. 2.2. INAA experiment A sample of dimensions 30 mm 10 mm was cut from each shard. After abrading the glaze away, the pure bodies were washed in an ultrasonic bath with deionized water three times, then dried at 105 °C for 8 h. After these steps, the pure body was ground into a powder of maximum granular diameter less than 74 lm with an agate mortar. About 30 mg of each powder sample was wrapped in aluminum foil of 99.999% purity. The wrapped samples were placed in the reactor of the Chinese Institute of Atomic Energy together with calibration standards and a quality control standard. They were irradiated for 8 h in a neutron flux of 6.9 1013 n cm 2 s 1. The calibration standards are single or multi-element solutions [15] and the quality control standard is the Chinese national certified reference material of rock (GBW07103) [16]. The c energy spectrum of each sample was measured by a HPGe detector, which is connected to a multi-channel analyzer, and processing with the Span 5.1 software package. The first measurement was made after cooling for 5–7 days with a live time of 2000 s. The second measurement was made after 18–20 days with a live time of 3000 s. Under these conditions, 19 elements, La, Sm, Na, U, Ce, Nd, Eu, Tb, Yb, Lu, Hf, Ta, Th, Sc, Fe, Co, Rb, Cs, Ba, were determined. The validation of the analytical method applied in these works was carried out by analysis of GBW07103. The results show that the experimental values are in good agreement with the certified ones (See Table 2). 3. Results and discussion The average values of each element in porcelain body of the Yuan and Ming dynasties are shown in Table 3. Values of Na, Fe, U, Yb, Ta, Rb and Cs in porcelain body of the Yuan dynasty are much higher than those of the Ming dynasty. The value of Ba in porcelain body of the Yuan dynasty is also distinctively different
from that of the Ming dynasty. It obviously shows that the elemental composition in porcelain body of the Yuan dynasty is different from that of the Ming dynasty. Fe greatly influences the porcelain body color since it can produce gray or black porcelain body in a reducing atmosphere [17]. The less Fe in porcelain body, the purer white the porcelain body appears. The average value of Fe2O3 in porcelain bodies of the Yuan dynasty is 1.39 ± 0.33%, while that of the Ming dynasty is 0.86 ± 0.19%. It shows that different raw materials for making porcelain body were used in the Yuan and Ming dynasties. This analytical result is in accordance with the history of manufacturing technology of Jingdezhen porcelain-producing field [18]. The scatterplot of Na and Fe is displayed in Fig. 1. All samples are clearly located on two regions of the plot. Samples of the Yuan dynasty are concentrated in the upper right region while samples of the Ming dynasty are concentrated in the lower left region. We can therefore use the concentrations of Fe and Na to classify these ancient Chinese white porcelains into the Yuan and Ming dynasties. Fe and Na are the characteristic elements of ancient Chinese white porcelain which were fired at Jingdezhen in the Yuan and Ming dynasties. The average values of each element in porcelain body of different eras of the Ming dynasty are shown in Table 4. Although the elemental composition is slightly different among Hongwu era, Yongle-Xuande era, Zhengtong-Tianshun era and ChenghuaZhengde era, they can not be completely distinguished by using the contents of any two or three elements. It is necessary to transform the original experimental data to separate them by mathematical methods. Principle component analysis (PCA) and the Fisher linear discriminant have been widely used in archaeology [19–21]. The main objective of PCA is to reduce the dimension of the observations through a linear transformation. Low dimensional linear combinations are often easier to interpret and serve as an intermediate step in a more complex data analysis. The objective
Table 1 The detailed information of experimental samples excavated from the sherd pit of Maojiawan in the city of Beijing, China.
Ming
Groups
Number
Age
Provenance
Yuan Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
16 11 20 49 20
Yuan dynasty (AD 1271–1368) Hongwu era of Ming dynasty (AD 1368–1398) Yongle to Xuande era of Ming dynasty (AD 1403–1435) Zhengtong to Tianshun era of Ming dynasty (AD 1436–1464) Chenghua to Zhengde era of Ming dynasty (AD 1465–1521)
Jingdezhen Jingdezhen Jingdezhen Jingdezhen Jingdezhen
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G. Xie et al. / Nuclear Instruments and Methods in Physics Research B 267 (2009) 821–824 Table 3 The average elemental values of each element in porcelain bodies of the Yuan and Ming dynasties. Groups
Number
Na2O (%)
Fe2O3 (%)
La (ppm)
Sm (ppm)
U (ppm)
Ce (ppm)
Yuan Ming
16 100
1.73 ± 0.33 0.68 ± 0.30
1.39 ± 0.33 0.86 ± 0.19
12.7 ± 3.8 14.7 ± 8.2
3.67 ± 0.81 3.68 ± 1.29
9.93 ± 2.86 5.21 ± 1.22
22.9 ± 4.9 20.0 ± 7.3
Yuan Ming
Nd (ppm) 16.9 ± 5.3 13.3 ± 6.6
Eu (ppm) 0.53 ± 0.19 0.58 ± 0.18
Tb (ppm) 0.74 ± 0.16 0.56 ± 0.16
Yb (ppm) 3.01 ± 0.22 1.51 ± 0.52
Lu (ppm) 0.24 ± 0.03 0.16 ± 0.03
Hf (ppm) 3.58 ± 0.30 3.27 ± 0.30
Ta (ppm) 9.07 ± 1.67 3.72 ± 0.23
Yuan Ming
Th (ppm) 9.7 ± 2.7 11.0 ± 4.2
Sc (ppm) 3.05 ± 0.88 3.27 ± 0.47
Co (ppm) 3.42 ± 1.85 3.71 ± 3.75
Rb (ppm) 553 ± 110 279 ± 43
Cs (ppm) 67.7 ± 21.7 30.9 ± 5.8
Ba (ppm) 156 ± 37 204 ± 46
Fig. 1. Scatterplot of Na and Fe in bodies of ancient Chinese white porcelain of the Yuan and Ming dynasties.
Fig. 2. The analytical result of PCA on all samples.
of using the Fisher linear discriminant is to build classification functions, and then classify an unknown object into previously defined categories. Fisher suggested finding a linear combination which maximizes the ratio of the between-group sum of squares to the within-group sum of squares to build classification functions [22]. Sometimes, this can be used to separate groups which were overlapping using PCA methods.
The result of PCA on all samples is shown in Fig. 2. Samples of the Yuan dynasty are located on the left region while samples of Hongwu era, Yongle-Xuande era, Zhengtong-Tianshun era and Chenghua-Zhengde era are distributed on the right region. This distribution is the same as the scatterplot of Na and Fe (Fig. 1). Samples of Hongwu era, Yongle-Xuande era, Zhengtong-Tianshun
Table 4 The average elemental values of each element in porcelain bodies of different eras of the Ming dynasty. Groups
Number
Na2O (%)
Fe2O3 (%)
La (ppm)
Sm (ppm)
U (ppm)
Ce (ppm)
Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
11 20 20 49
0.20 ± 0.24 0.74 ± 0.29 0.65 ± 0.22 0.78 ± 0.25
1.04 ± 0.09 0.75 ± 0.09 1.05 ± 0.22 0.80 ± 0.13
29.7 ± 9.2 11.4 ± 4.4 20.8 ± 7.2 10.1 ± 3.7
6.05 ± 1.21 3.59 ± 0.98 4.37 ± 0.72 2.90 ± 0.67
6.03 ± 0.67 5.36 ± 1.81 5.78 ± 0.91 4.74 ± 0.93
29.9 ± 4.0 16.9 ± 5.4 25.9 ± 6.5 16.6 ± 5.0
Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
Nd (ppm) 26.1 ± 6.5 11.7 ± 4.5 16.9 ± 4.6 9.7 ± 2.6
Eu (ppm) 0.90 ± 0.27 0.49 ± 0.11 0.65 ± 0.14 0.52 ± 0.10
Tb (ppm) 0.90 ± 0.16 0.53 ± 0.11 0.59 ± 0.10 0.48 ± 0.08
Yb (ppm) 2.55 ± 0.35 1.60 ± 0.36 1.75 ± 0.32 1.15 ± 0.15
Lu (ppm) 0.22 ± 0.04 0.14 ± 0.02 0.16 ± 0.03 0.15 ± 0.02
Hf (ppm) 3.37 ± 0.28 3.20 ± 0.20 2.98 ± 0.27 3.39 ± 0.26
Ta (ppm) 5.85 ± 0.71 3.36 ± 1.32 3.75 ± 1.24 3.38 ± 0.71
Hongwu Yongle-Xuande Zhengtong-Tianshun Chenghua-Zhengde
Th (ppm) 16.7 ± 1.7 11.0 ± 4.3 12.9 ± 2.5 8.9 ± 3.4
Sc (ppm) 3.84 ± 0.70 2.99 ± 0.20 3.48 ± 0.55 3.17 ± 0.28
Co (ppm) 6.01 ± 1.76 1.67 ± 0.58 6.35 ± 3.08 2.94 ± 4.25
Rb (ppm) 325 ± 23 282 ± 57 269 ± 47 271 ± 31
Cs (ppm) 29.6 ± 10.6 29.5 ± 4.5 31.9 ± 6.9 31.4 ± 4.3
Ba (ppm) 137 ± 26 201 ± 48 192 ± 34 224 ± 36
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elemental difference between the Yuan and Ming dynasties is larger than the difference among Hongwu, Yongle-Xuande, Zhengtong-Tianshun and Chenghua-Zhengde eras of the Ming dynasty. The elemental compositions in porcelain body of Hongwu era, Yongle-Xuande era and Chenghua-Zhengde era are slightly different, indicating temporal chemical variation. However, the elemental composition in porcelain body of Zhengtong-Tianshun era is mainly similar with that of Hongwu and Yongle eras and no characteristic discriminating chemical feature was found for the Zhengtong-Tianshun era. Acknowledgements The authors greatly appreciate the financial support from the Knowledge Innovative Program of Chinese Academy of Sciences (No. KJCX3.SYW.N12), The Youth Innovative Foundation of Institute of High Physics of Chinese Academy of Sciences (No. 542007IHEPZZBS546100), Natural Science Foundation of Beijing City (No. 1082009) and National Natural Science Foundation of China (Nos. 10705032 and 10675143). References
Fig. 3. The analytical result of Fisher linear discriminant on all samples.
era and Chenghua-Zhengde era are not well separated. This means that the elemental difference between the Yuan and Ming dynasties is larger than the difference among Hongwu era, YongleXuande era, Zhengtong-Tianshun era and Chenghua-Zhengde era of the Ming dynasty. The raw materials for making porcelain bodies were changed in the period between the Yuan and Ming dynasties. Using the Fisher linear discriminant to interpret the experimental data, the result is shown in Fig. 3. Samples of the Yuan dynasty are still separated from that of the Ming dynasty. Samples of Hongwu era, Yongle-Xuande era and Chenghua-Zhengde era are separately distributed on the left region of the plot. It shows that these groups can be clearly distinguished by their elemental body composition so the temporal chemical variation among Hongwu era, Yongle-Xuande era and Chenghua-Zhengde era is clearly observed. Samples of Zhengtong-Tianshun era are overlapping with the samples of Hongwu era and Yongle-Xuande era. A characteristic discriminating chemical feature in porcelain bodies of ZhengtongTianshun era is not found. 4. Conclusions INAA has been used to analyze the elemental composition in body of ancient Chinese white porcelain excavated from Maojiawan. According to the experimental data, the elemental composition is different in porcelain body of the Yuan and Ming dynasties. Fe and Na are the characteristic elements which can be used to classify shards into these two dynasties. It is obviously shown that different raw materials for making porcelain body were used in the period between the Yuan and Ming dynasties. The results from PCA and the Fisher linear discriminant show that the
[1] The Chinese Ceramic Society, The History of Chinese Pottery and Porcelain, Cultural of Relics Publishing House, Beijing, 1982, p. 181. [2] Fukang Zhang, Scientific Technology of Ancient Chinese Porcelain, Shanghai People’s Fine Arts Publishing House, Shanghai, 2000. p. 67. [3] Jiazhi Li, The History of Chinese Scientific Technology Ceramic Volume, Science Publishing House, Beijing, 1998. p. 143. [4] Beijing Institute of Cultural Relics, Excavation Report on a Ming Period Porcelain Burial at Maojiawan, Science Publishing House, Beijing, 2007, p. 126. [5] Huibing Li, The Basic Knowledge About Identifying Ancient Chinese Porcelain, Forbidden City Publishing House, Beijing, 2001. p. 100. [6] Naizhang Zheng et al., Chemical composition analytical methods being instruments on the identifications and studies of ancient ceramics by instruments, China Ceramic 43 (5) (2007) 52. [7] Songlin Feng et al., Application of nuclear analysis techniques in ancient Chinese porcelain, Nucl. Phys. Rev. 22 (1) (2005) 13. [8] Dongyu Fan et al., Study of elements in Yue Kiln ancient celadon by SRXRF and factor analysis, Nucl. Techn. 25 (10) (2005) 136. [9] Xiangqian Feng et al., Ding and study of discriminating criteria, Nucl. Techn. 25 (10) (2005) 827. [10] H.S. Cheng et al., The non-destructive identification of early Chinese porcelain by PIXE, Nucl. Instr. and Meth. B 219–220 (2004) 16. [11] Guoxi Xie et al., Study on ancient Chinese imitated GE ware by INAA and WDXRF, Nucl. Instr. and Meth. B 264 (2007) 103. [12] Guoxi Xie et al., Trace element analysis for ancient Chinese celadon porcelain excavated from the Maojiawan site, J. Chin. Ceramic Soc. 35 (9) (2007) 1222. [13] Guoxia Li et al., Application of neutron activation analysis in study of ancient ceramics, Nucl. Phys. Rev. 17 (4) (2000) 248. [14] Beijing Institute of Cultural Relics, Excavation Report on a Ming Period Porcelain Burial at Maojiawan, Science Publishing House, Beijing, 2007, p. 474. [15] R.R. Greenberg, Accuracy in standards preparation for neutron activation analysis, J. Radioanal. Nucl. Chem. 179 (1) (1994) 131. [16] List of Reference Materials, China Measurement Press, Beijing, 2000, p. 60. [17] Fukang Zhang, Scientific Technology of Ancient Chinese Porcelain, Shanghai People’s Fine Arts Publishing House, Shanghai, 2000. p. 3. [18] Jiazhi Li, The History of Chinese Scientific Technology, Ceramic Volume, Science Publishing House, Beijing, 1998. p. 325. [19] Guoxi Xie et al., Study on the provenance of ancient porcelain excavated in Maojiawan ruin by WDXRF analysis, Nucl. Techn. 30 (4) (2007) 1. [20] Jihao Zhu et al., Study of provenance character on ancient porcelain of Yue Kiln at Silongkou with NAA, J. Radioanal. Nucl. Chem. 272 (3) (2007) 545. [21] D. Zhu et al., PIXE study on the provenance of Chinese ancient porcelain, Nucl. Instr. and Meth. B 249 (2006) 633. [22] W. Härdle, L. Simar, Applied Multivariate Statistical Analysis, Springer, Berlin, 2003. p. 323.