(1) Authenticity.
(2) dating
(3) Judge the advantages and disadvantages
(4) Break the kiln mouth
Appraisal method of ancient porcelain
Includes the following three aspects:
1. Classification is to classify the last similar vessels (including the same vessel shape and the same decorative theme) into the development sequence, find out their similarities and differences, and explore the development laws and characteristics of each period.
2. The comparative method is mainly based on archaeological excavations and objects with stratigraphic age as the standard objects, and compares the objects that need to be identified with them, so as to draw the identification conclusion.
3. The identification method is to compare and contrast the objects that need to be identified by using the characteristics of the same kind or different kinds of objects at the same time, so as to draw a reasonable conclusion of comprehensive identification.
However, these methods are too abstract for beginners. In fact, in the case that the products of a certain era have not yet reached the "standard", the method of "looking at both ends and confirming in the middle" can be adopted. For example, to identify Hongwu blue-and-white, we should first look at the "perfect" blue-and-white in Yuan Dynasty, and then look at the blue-and-white in Yongle and Xuande in Ming Dynasty, as well as those blue-and-white porcelain that are not like Yuan Blue-and-white but have some characteristics of Yongle and Xuande blue-and-white porcelain in Ming Dynasty. It's Ming Hongwu blue and white porcelain. Because the products of any period will inevitably have many factors of "connecting the past with the future". When appraising, look forward, think backward, think left and right, and you will come to the correct conclusion.
When a product that needs to be identified is in front of us, how to analyze its firing age and kiln mouth? That is to say, what aspects of the utensils themselves can reflect their real firing age and kiln mouth? We call the factors that can reflect the firing time and kiln mouth the age factor. It mainly has the following aspects:
1. shape
It mainly depends on the physical characteristics of the mouth, neck, shoulders, abdomen, wall, feet, flow, grip and tie, as well as the thickness and weight of the carcass. In addition, some unique and well-known shapes of each era should also be kept in mind, because they are often copied by future generations. For example, the hand-pressed cup of Yongle in Ming Dynasty, the chicken cylinder cup of Chenghua, the phoenix tail statue of Kangxi in Qing Dynasty, the white deer statue of Qianlong and the heart-turning bottle. Only by remembering the shape characteristics of the real thing can we see through the fake at a glance.
decorate
Including decorative methods (painting, glass, carving, painting, carving, carving, queuing, rubbing, printing, pasting, etc.). ), theme, composition, pattern image, painting, etc. Because decoration changes with the changes of modeling, technology, materials and people's aesthetic requirements, the upgrading and changes of decoration are more frequent and active than other appraisal factors, so it is more important to analyze this factor in appraisal. Take Jingdezhen's glazed porcelain as an example, which appeared in the middle and late Yuan Dynasty. At that time, there were only three colors, red, yellow and green, and the painting method was the same as that of Yuan Blue and White, with bold and bold brushwork, vivid and natural. In the early Ming Dynasty, Hongwu not only inherited the painting style of Yuan Dynasty, but also appeared double-sided alum red. In Yongle and Xuande, there were blue and white hats and red hats, with magnificent patterns and dignified and gorgeous colors. Chenghua Doucai has various painting methods, such as covering, dyeing, adding and filling, but all of them are flat painting, "flowers have no negative side, leaves have no negative side", and the appearance is light and beautiful. The multicolored colors of Jiajing and Wanli are mainly painted with over-glaze colors. Painted blue and white, but the proportion is small. At this time, a new emerald color was produced, and the black material was hooked with glue, but the middle of the black line was slightly brown. The pattern layout is more gorgeous than Chenghua's fighting color, and the pen is loose and simple. The multicolored color of Kangxi in Qing Dynasty was deeply influenced by the layout illustrations in the early Ming Dynasty. The composition is balanced and full, the image is exaggerated, the lines are soft and firm, the colors are bright and clear, the red and green are bright and antique. The black in Kangxi's colorful paintings is deep and bright, and it is no longer slightly brown. The black material and alum red are mixed with oil, and the principal is also used in the colorful paintings. Kangxi's multicolored colors deeply influenced later generations, and Ting Anne and Daohou also imitated many things, but none of them were as vivid and natural as Kangxi's multicolored colors and Gu Zhuo's beauty.
3. Fetal glaze
When identifying fetal quality, we can start with the unglazed part of the foot and pay attention to the purity of fetal clay and the rigor of sintering. Due to the different pottery-making methods of the times, there were more metal impurities in the tire soil before the Ming Dynasty than in the Qing Dynasty and the Republic of China. For example, the famous Yong Xuan fine sand bottom device can be seen in the exposed tire with dark brown stars or flint red formed by natural oxidation of metals; Later, the carcasses of the Qing Dynasty and the Republic of China were copied, but it was because the mold was too fine and there was no such oxidation spot, which became the fatal defect of the fake. In addition, in the Ming Dynasty, the light on the carcass was mostly flesh red. The transparent matrix of Ming Chenghua is ivory white and pink white. But the imitations of the Qing Dynasty and the Republic of China were all blue and white. Kangxi porcelain in the Qing Dynasty was pure, delicate and hard, which was behind the imitations in the late Qing Dynasty. As for the identification of glaze, we should mainly pay attention to the thickness of enamel color, old and new luster, the thickness of glaze layer, the size and density of bubbles. For example, the glazes of Ming porcelain are all blue and white to varying degrees, and the full glaze and blank glaze are mostly inconsistent; In the early Ming dynasty, colorless natural glaze opening and shrinking often occurred; There are subtle differences between Xuande orange peel glaze in Ming Dynasty and the small ripples of imitators in Yongzheng in Qing Dynasty and after the late Qing Dynasty and the Republic of China. The glaze of Kangxi porcelain in Qing dynasty has a sense of compactness, the blue glaze is hard and bright, the white glaze is broken and bubbles are broken. . . . These have typical characteristics of the times, and it is most convincing to see through fakes. In addition, judging from the old and new luster of the glazed surface, many imitators mystify and make the glazed surface of the imitation old: burying the soil, polishing, slipping the medicine, boiling the tea, and even slightly damaging it to show the appearance of the soil. Of course, these unnatural old luster, there is absolutely no ancient porcelain over time naturally formed "crisp light" phenomenon.
4. Manufacturing technology and decoration method
With the progress of science and technology, porcelain-making technology and firing methods are constantly improving and perfecting. For example, Jingdezhen in the Five Dynasties adopted the method of "Zhi Ding reburning" without box, leaving about 7- 18 traces of Zhi Ding on the edge and insole. At the beginning of the Northern Song Dynasty, three or four Zhi Ding were placed on the foot of the utensils, and then they were boxed (one box for one utensil) and fired in the kiln, leaving three or four Zhi Ding marks on the foot of the products. Then Zhi Ding wouldn't have to use it. Install a washer-shaped pad cake on the inner bottom of the vessel, which is smaller than the inner diameter of the hoop foot and about higher than the hoop foot, and then put it into a sagger, so that the inner bottom of the hoop foot of the product leaves traces of the washer or pad cake. Due to the appearance of over-burning, Mangkou porcelain was produced in the late Northern Song Dynasty. For example, from the Yuan Dynasty to the Ming Hongwu, the bottoms of big bottles and big cans were connected separately, and this method was not adopted after Hongwu. In the Hongwu period of Yuan and Ming Dynasties, the high foot of the cup was connected with the upper cup with mud, and it was connected with glaze after Hongwu. There were many obvious interfaces when bottles and cans were formed in Ming Dynasty. These small features caused by technology, assembly and firing can not be ignored in identification.
5. Money knowledge
Jingdezhen porcelain has officially had the title of emperor since the Yongle official kiln porcelain in Ming Dynasty, and it is very common to promote virtue. Since then, the form and content of style have become more and more abundant. The common ones are the emperor's year number, entrusted money, fake money, year of dry support, borrowing money, hall, porch, house name, name, auspicious words, flower pledge, window lattice and so on. Because the imperial kiln factory in Ming and Qing dynasties has special funds, there are other chapters with the characteristics of Ming and Qing dynasties. In the Ming and Qing Dynasties, the signatures of folk kiln products were made according to their own wishes, and the handwriting was random, which was second only to the official kiln porcelain style in identification. At the same time, we should pay attention to the law that "official kilns must be young, but they are not necessarily young" (except for a few official kilns, such as the early Kangxi period).
6. Overall style
Porcelain, like other works of art, local style and personal style are also integrated into the style of the times, so it is also a component of the style of the times. Therefore, grasping the overall artistic style of China porcelain in different times is also very beneficial for identification. For example, China's Song Dynasty porcelain is exquisite in shape, exquisite and elegant in design, light, handsome, quiet and elegant in style, and Jingdezhen's Song Dynasty shadow play products are also integrated into the style of this era. China's Yuan dynasty porcelain has a heavy matrix, dignified shape and bold and powerful decorative patterns, and Jingdezhen's Yuan blue and white flowers fully reflect the flavor of the times. Grasping the overall style of an era is of great benefit to our identification of ancient porcelain. With the continuous development of science and technology, various advanced instruments have come out one after another, making more and more methods to identify porcelain. Generally speaking, there are three advanced means.
First of all, the accelerator C 14 dating method is mainly suitable for dating some pottery in prehistoric sites. This method is considered to be highly accurate and has been adopted by many archaeologists.
Secondly, the "thermoluminescence" technology is used to determine the age of porcelain. The basic principle of this method is to obtain the firing age of porcelain by measuring the thermoluminescence of mineral crystals in the porcelain matrix. Because there are mineral crystals such as chronological and feldspar in porcelain, these crystals play an important role in thermoluminescence dating technology. In the process of high-temperature firing, porcelain burned out its original age data, but when it was fired out of the kiln, it started its age again. Therefore, it is a scientific method for scientists to use this principle to identify porcelain. However, this method has two fatal weaknesses: first, it needs sampling during identification, that is, damage sampling of the identified cultural relics, that is, damage detection; Second, artificial counterfeiting can be carried out, that is, imitations and fakes are irradiated with radiation, which increases the thermoluminescence age of porcelain and leads to errors. Therefore, at present, the identification of pottery mainly adopts the "thermoluminescence" detection method.
Thirdly, the "nondestructive" detection method is adopted to overcome the shortcomings of the above destructive detection. That is, using high-tech direct measurement. A method for displaying raw materials and chemical components of porcelain tires and glazes and performing cluster arrangement. Due to different times, the raw materials and chemical composition of kiln mouth and various ceramics are different, while the content of porcelain in the same era, kiln mouth and similar categories is roughly the same. Non-destructive identification is to use "clustering parallel" to digitally analyze and compare the different contents of ceramic glaze, so as to achieve the purpose of distinguishing between true and false. The richer the cultural relics database is, the more accurate the parallelism study will be, and the more scientific the result of the comparison between authenticity and falsehood will be. Even so, now fluorescence energy spectrum analysis is also applied to the detection of ceramics, which plays an important role in the auxiliary identification of ceramics.
This nondestructive testing method is feasible and scientific at present, because there is almost no damage to cultural relics, even large cultural relics, and the sampling is extremely fine. Just as doctors first diagnosed tuberculosis manually, it is more reliable to use modern scientific instruments. The same is true of cultural relics appraisal. In addition to the traditional manual identification methods, scientific instruments are also used for auxiliary identification. It can be said that this is the inevitable trend of correct identification of cultural relics in the future.
In a word, the identification of China ancient porcelain can definitely identify the quality and authenticity from embryo, shape, glaze color, decoration, firing technology, style and so on. No matter the authenticity of any era, it is the product of a specific era. Although there are many imitations in the later period, they are imitations of another era after all. As long as all kinds of factors are considered comprehensively, the so-called "genuine" fakes can't escape the eyes of the appraisers.
4) Wuzhou Kiln is located in Jinhua, central Zhejiang. During the Three Kingdoms period, the celadon of Wuzhou kiln was generally blue-gray, with rough section, rough treatment of porcelain mud, incomplete firing and poor vitrification. The glaze layer is uneven in thickness and often condenses into sesame spots, usually light blue, blue gray or yellowish blue, with dense cracks. In the place where the fetal glaze is not tightly combined and the glaze is cracked, milky yellow crystals often precipitate, which is a unique phenomenon of celadon in European kilns. Because the soil layer in this area is siltstone belt, porcelain clay minerals are scattered, and the ore layer is very small and thin, which is not easy to mine. Therefore, in the late Jin Dynasty, the craftsmen of European kilns creatively used red clay, which is ubiquitous, easy to be mined and brittle, and has good plasticity as the green body. However, due to the high content of iron oxide and titanium oxide in clay, the tire color after firing is deep purple, which affects the color of green glaze, so a fine layer of white cosmetic soil is coated on the tread to cover up the tire color. Because there is cosmetic soil outside the tire, the glaze layer is moist and soft, and the glaze color is slightly blue-gray or blue-yellow brown, but the glaze cracking and crystallization are more serious than porcelain with porcelain soil as the tire. In the Southern Dynasties, the glaze layer of European kiln porcelain was generally yellow, and the fetal glaze had poor adhesion and was easy to peel off.
5) Deqing Kiln is located at the western end of Hangjiahu Plain, connecting Yuhang County in the south and Xing Wu County in the north. During the Tianmu Mountain period, Dongming River flowed through the county from south to north and then flowed into Taihu Lake, with convenient land and water transportation. Deqing kiln is a porcelain kiln burning black porcelain and celadon, which mainly produces black porcelain. The tires of black porcelain are mostly brick red, purple or light brown. The chemical composition of the porcelain tire is very consistent with that of the Eastern Jin porcelain tire of the European kiln. The content of iron oxide in the container is 3%, and titanium oxide is about 1%. Red clay can be used as a blank, or a proper amount of purple mud can be mixed into porcelain clay. Celadon tires are generally dark gray or light gray, and a few porcelain tires with high iron content are purple. Because the tire color is dark, it is not good for the color of green glaze. Generally, a layer of milky white cosmetic soil is applied outside the tire to improve the color of green glaze, make the tread smooth and improve the appearance of finished products. Deqing kiln celadon glaze is dark, generally turquoise, bean green or turquoise. Uniform glaze layer and good luster. Black glaze layer, one of the most outstanding products, is moist in glaze color, black as paint, and shiny in glaze, which is comparable to lacquerware. The main colorant of this black bright glaze is iron oxide, the content of which is about 8%. The firing history of Deqing kiln is not long, from the Eastern Jin Dynasty to the early Southern Dynasties, which is 100 years. However, due to the popularity of black glazed porcelain, products are sold to many places in Zhejiang and Jiangsu, and even as far away as Sichuan.
6) Others: In Sichuan, Hunan, Hubei, Jiangxi and other places located in the middle and upper reaches of the Yangtze River, it was found that the time of firing porcelain was later than that in Jiangsu and Zhejiang areas in the lower reaches of the Yangtze River, and it was probably the Jin Dynasty that built kilns to make porcelain.
Jingchu area has produced high-quality primitive porcelain and a small amount of celadon during the Three Kingdoms and Wu Dynasties. The tire is purplish red or light gray, coated with yellow-brown glaze or blue glaze, and the glaze layer is uneven in thickness and easy to fall off. In the Western Jin Dynasty, porcelain clay was used as the blank, and the fetal quality was delicate, showing bluish gray or grayish white. The tread is coated with yellow-green glaze, some are near yellow, some are near green, some are green in yellow, and a few are brown. Glaze ice cracks, poor combination of fetal glaze, often peeling phenomenon, or even complete peeling. After entering the Eastern Jin Dynasty, the porcelain tires were grayish white, a few were gray or purple, and there were green or turquoise glazes on the outside. Because the firing temperature of tire glaze is inconsistent, the expansion coefficient does not match. Glaze is usually cracked by ice and easy to fall off, so the quality of porcelain is not high.
Celadon is widely found in the tombs of the Southern and Northern Dynasties in Zhao Hua, Guangyuan, Mianyang, Zhangming and Chengdu. The tires of these porcelains are gray and the glazes are blue and yellow. Slices are many, easy to peel, with wax tears. During the Southern Dynasties, the embryo of Qionglai kiln porcelain was delicate and light gray, and the glaze color was generally green with yellow or yellow, and the glaze was often cracked by ice and easy to fall off.
Jiangxi porcelain in the Western Jin Dynasty, after elutriation, is fine in texture and blue-gray or gray-white. Blue-green, beige or yellow-green glazes are applied inside and outside the utensils, but the outer wall is not glazed to the end, and there seems to be no intermediate layer between the fetal glazes, which is easy to glaze and crack on the ice. Porcelain tires in the Eastern Jin Dynasty are delicate and gray-white, and the glaze color is mostly bluish yellow, and a few are bean color. The porcelain tires of the Southern Dynasties were fine and white, but the firing temperature was not high and they were not completely vitrified. The glaze layer falls off easily. Glazed in the Western Jin Dynasty, the abdomen is decorated with printed patterns, with auxiliary heads on both sides, which has obvious characteristics of the Han Dynasty. This kind of blue glaze has been unearthed in large quantities. The three-legged statue of green glaze is also decorated with printed patterns, with three bear feet under it, animal patterns on both sides and auxiliary heads on the other two sides. The shape and decoration also have the characteristics of the Han Dynasty. The granary of the Jin Dynasty has a main pot in the center of the upper part and four small pots around it. It is a slightly modified version of the five-joint pot and five-tube bottle in the Eastern Han Dynasty, with reliefs, Buddha statues, birds and beasts on it and pots on the lower part. The barn is a true portrayal of the tomb owner's manor before his death, and it is also their hope to live a well-fed and affluent life as before. Barns have been unearthed in the tombs of Wu and Western Jin Dynasties south of the Yangtze River. There is an inscription that says "Lin", which is for rice. The grain loader in the north is called a barn. From the above objects, we can see the shape, types and decorative characteristics of porcelain in the Western Jin Dynasty. Many shapes are taken from bronzes and pottery in the Han Dynasty. Pots and cans are relatively short in shape, and bronze wares are also used for reference in decoration. Most pots, basins, washings, bowls and other utensils are decorated with banded printed patterns on the shoulders and abdomen, with the first circle and animal patterns in the middle.
The types of porcelain in the Eastern Jin Dynasty are similar to those in the Western Jin Dynasty, but the obvious change in shape is that the shape of porcelain develops to a slim height, and the shoulder system is mostly bridge-shaped, which is used to be called bridge-shaped. Light is the main decorative element, and a small number of utensils have brown spots on the mouth edge, shoulders and abdomen, animal eyes and other parts, which forms the decorative characteristics of utensils in this period. From the evolution of the most representative chicken-headed pot (can), we can see the characteristics of porcelain modeling and decoration in various periods. In the Western Jin Dynasty, the head of a chicken jar has a double tie on the shoulder, and the double tie is decorated with the head and tail of a chicken. In the early Western Jin Dynasty, the largest belly diameter of the jar was in the middle, and then the center of gravity moved up, and the largest diameter was at the shoulder. The abdominal diameter is roughly the same as the height of the pot, so it gives people the feeling of being short and fat. The shoulders are decorated with prints. In the Eastern Jin Dynasty, the head of the chicken-headed pot is a pan, which is long and bridge-shaped, and some of the heads are decorated with brown dots. The head of the chicken has a neck of about one inch, and the tail of the chicken has evolved into a pot handle. The height of the pot is obviously larger than the abdominal diameter, so it gives people a slender feeling. In addition to the blue glaze, there is also a black glazed chicken head pot. Black glaze appeared in the Han Dynasty and continued to be fired in the Eastern Jin Dynasty. At present, only two kilns in Yuhang and Deqing, Zhejiang Province are found to burn black glaze, and both kilns also burn blue glaze. In the Southern Dynasties, the body of the chicken-headed pot was longer, the handle of the pot developed upward, and the double-line lotus petal pattern appeared on the decoration. The appearance of lotus petal pattern is related to the introduction of Buddhism in the Eastern Han Dynasty. Other utensils in this period, such as plates, bowls and cans, were also decorated with lotus petals, which formed the decorative characteristics of this period. In the Eastern Jin Dynasty, there were sheep head pots in addition to chicken head pots, the number of which was less than that of chicken head pots, but the number unearthed at present is gradually increasing. In the Eastern Jin Dynasty, many tombs of the two Jin Dynasties were unearthed, and the modeling of the Western Jin Dynasty inherited the characteristics of the Han Dynasty. There are holes in the sphere, and there are three feet between the sphere and the bearing plate. In the Eastern Jin Dynasty, pillars were used to connect the sphere and the bearing plate.
Lotus-covered double-system pot in the Southern Dynasties, short-flowing, lifting hands up. There are not many unearthed pots of this kind. The whole body is decorated with lotus flowers bent down, and the flying in the cave art also appears on the lotus statue, as well as flowers, animal faces and leaves. , the decoration is extremely rich. Lotus statues have also been unearthed in the south, which are not as grand as those in the north. The carcass of the northern lotus statue is relatively thick, and the glaze thickness is close to black. To be sure, during the Southern and Northern Dynasties, this kind of ware was fired in the north and south, but no kiln site was found in the north and south. Only specimens with similar characteristics to the lotus statue were found in Hebei, and embossed lotus petals were found in Zibo Kiln, which is only a clue and needs further investigation. In the Northern Dynasties, there were embossed lotus petals on the green glazed lotus jar, which were printed and pasted. The six-bridge shoulder was used in the Eastern Jin Dynasty, but it was thicker than the Eastern Jin Dynasty. This kind of unearthed cultural relics is increasing day by day. In the late Northern Dynasty, the iron content in the glaze was low, and the Hu glaze was light blue, which was close to that in Sui Dynasty. The decal cans in the Northern Dynasties had high iron content, dark brown glaze and kiln change. The yellow glazed green colored jars unearthed from the tomb of Northern Qi Dynasty in Henan Province are generally considered to be the predecessor of the three colors of Tang Dynasty. Tang San is usually yellow, green and white (blue). Its development process is: from monochrome glaze in Han Dynasty to yellow glaze and green color in Northern Dynasty to tri-color in Tang Dynasty. Brown glazed flat bottle in the Northern Dynasties, seven centimeters high, with dancing figures printed on both sides. The figure modeling and beading patterns have a Western Asian style. This kind of flat bottle appeared in the late Northern Dynasty and was fired in Sui and Tang Dynasties.
During the Southern and Northern Dynasties, porcelain continued to develop after the Jin Dynasty. Fortunately, northern porcelain is developed and there are some high-quality utensils. It changed the situation that porcelain was only fired in the south in the past and laid the foundation for the development of northern porcelain.
Identification of Porcelain in Sui, Tang and Five Dynasties
Identification of (1) celadon
Although the situation of "blue in the south and white in the north" was formed at that time, the number of celadon unearthed in Sui, Tang and Five Dynasties was still more than that of white porcelain, and the celadon in Yueyao represented the highest level of celadon in Tang and Five Dynasties. Now according to the kiln mouth description is as follows.
In the early and middle period of Tang Dynasty, the fetal quality of Yueyao kiln was gray and loose, and the glaze layer was easy to peel off. In the late Tang Dynasty, the raw materials of Yue Kiln were processed very finely. Porcelain clay has been well crushed and washed, and has been kneaded before molding, so the fetal quality is fine and dense, with no delamination and few pores, and it is gray, light gray or light purple. Regular shape, smooth tread of bowls, plates and pots, and even glaze color; Especially in the later period, glaze treatment and glazing technology have also been greatly improved. The glaze layer is even, with few fine lines and glaze shedding. It is yellow-green or yellow, moist and opaque, and bare as ice. Yue kiln porcelain was called "secret color porcelain" in the Five Dynasties. Qing people commented that "its color is like a vessel, but it is clear."
Ouyao is located in Wenzhou, Yongjia and Ruian in the south of Zhejiang. The biggest difference between Ou kiln and Yue kiln porcelain is that the porcelain body of Ou kiln is yellow or light yellow, and the glaze is easy to peel off; In the later period, pure cyan or bluish yellow appeared around, which moistened jade, closely combined with fetal glaze, and rarely inhibited glaze, and the porcelain-making technology was significantly improved.
Wuzhou Kiln ranks third among the celadon kilns in Tea Classic written by Lu Yu in Tang Dynasty, namely "Bowl, Yuezhou, Dingzhou and Wuzhou". In fact, the quality of Wuzhou kiln porcelain is not high, and most of them are rough, but there are many porcelain workshops and the production is developing rapidly. Now Jinhua, Lanxi, Yiwu, Dongyang, Yongkang, Wuyi, Jiangshan and other counties have vast areas. Among them, Dongyang, Jinhua, Wuyi and other counties have found dozens to 200 porcelain kiln sites, all of which have several miles of porcelain concentration areas. This shows that the production scale of Wuzhou kiln developed rapidly in the Tang Dynasty, especially in the Five Dynasties. There are many similarities in product types and shapes with Ou Kiln and Yue Kiln, but the difference is that the tire color is dark gray or purple, the glaze color is bluish yellow with gray or purple, the glaze is dotted with milky white, the glaze color is bluish yellow with gray or purple, and the glaze is dotted with milky white, which also appears in the cracks of the glaze layer. This is a common phenomenon of Wuzhou kiln porcelain since the Six Dynasties. After the middle and late Tang dynasty, the porcelain of Wuzhou kiln became rough, and its production was far less fine than that of Ou kiln and Zhao kiln.
(2) Identification of white porcelain
Xing kiln is the most famous white porcelain kiln in Tang Dynasty. In the middle of the 9th century, Guo Daoyuan, a musician in Duanjie Yuefu Miscellany, recorded that "Yueou and Xingou are used to reduce water, and the sound is better than the sound of the square." This passage shows that Yao Xing white porcelain has the best quality, solid and dense fetal bones, and it can play beautiful music as a musical instrument like Yueyao porcelain. According to the investigation of Light Industry Bureau of Lincheng County, Hebei Province 1980, the famous Xing Kiln in Tang Dynasty should be located in Qicun, which borders Neiqiu. What is recorded in the Supplement to National History should be general, just like Ding Yao is not in Dingzhou, but in Quyang, which is adjacent to Dingzhou. The whiteness of white porcelain in Qicun kiln in Tang Dynasty is very high, far better than Quyang kiln and Mixian kiln. At the same time, it is light green at the tire thickness. Hebei Quyang kiln has a thick tire bone and a thick section, but it is well sintered. The glaze is thick, the glaze color is generally blue and white, the glaze water condensation is mostly turquoise, and the glaze is open. If the tire quality is good, the tire color is white and the glaze color is bright and moist. If the tire color is slightly yellow, in order to achieve the white effect, first coat a layer of white cosmetic soil on the carcass, and then cover it with transparent glass glaze.
White porcelain was produced in Gongxian kiln in Henan province from the early Tang Dynasty, and flourished from Wu Zetian to Xuanzong, and then gradually declined. The white porcelain of Gongxian kiln is thick, and the place with thick glaze is turquoise or bluish white.
Shengmeiting, Shihuwan and Huangnitou in Jingdezhen, Jiangxi Province are the earliest kiln sites where white porcelain was found in the south. There are five generations of white porcelain specimens unearthed, of which Shengmeiting is the most abundant. Porcelain tire is more important than Gongxian kiln, while porcelain glaze is thicker than Gongxian kiln, and the glaze color is generally white and blue.
(3) Identification of yellow glazed porcelain
There are often some black glazed porcelains in the tombs of the Tang Dynasty, which were found in the tombs of the early Tang Dynasty. Among all kinds of porcelains in the Tang Dynasty, yellow glazed porcelains are not as good as white porcelains in Xing kilns and Ding kilns, and celadon in Yue kilns is even more famous, but its historical position in Tang porcelains can not be ignored.
Lu Yu commented on the tea bowls produced by the six major porcelain kilns in the Tang Dynasty, ranking the products of Anhui Shouzhou kiln after Yue, Ding, Wu and Hongzhou kiln, and pointed out: "Shouzhou porcelain is yellow, and the tea color is purple." The era of porcelain burning in Shouzhou kiln began in Sui Dynasty, and the Tang Dynasty was its heyday, which lasted for more than 200 years. Shouzhou kiln porcelain is popular with cosmetic soil, and the surface is transparent glass glaze. The glaze is smooth with small lines. The glaze color is mainly yellow, including sallow, eel yellow and yellow-green. The makeup soil is smooth and delicate. Glaze with dipping glaze, the thickness of glaze layer is uneven and the glaze color is different. If the glaze color and cosmetic soil are not well combined, there will be a phenomenon of glaze removal.
Compared with the regularly rotating white porcelain bowls unearthed at the same time, the yellow glazed porcelain bowls fired in Beizhen, Quyang, Hebei Province obviously belong to a kind of folk coarse porcelain, with thick carcass, white glaze in the jar and yellow glaze outside, and the color tone is not as pure as that of Shouzhou kiln, mostly yellow-brown and thick tire.
The yellow porcelain burned in Jiaxian kiln is mainly bowls, cans and pots, with white inside and yellow outside, and the mouth is not glazed; So is Hunyuan kiln. The firing of yellow glaze in Tang Dynasty is not the difference of raw materials, but changes the firing atmosphere of the kiln. Reducing flame was used to burn blue glaze in Sui Dynasty and yellow glaze in Tang Dynasty, so the tire color changed from bluish gray to white with yellow.
(4) Identification of black glazed porcelain
The appearance of northern black porcelain was more than 300 years later than that of Jiangnan. In the 1970s, black glazed porcelain was found in the tombs of the Northern Qi Dynasty, which was between glazed surface and black sauce. At present, seven counties in Shanxi, Henan and Shandong provinces have found kiln sites for firing black porcelain in the Tang Dynasty, mainly in Henan, and black porcelain has been found in five kiln sites. The carcass is thick and the tires are gray.
(5) Identification of flower glaze
Flower glazed porcelain is another new creation in Tang porcelain. Decorate black glaze, yellow glaze, yellow-brown glaze, sky blue glaze or tea powder glaze with sky blue or moon white spots. Some spots are arranged regularly, some are randomly added, and some are like waves. Because they are all decorated on dark glaze, they set off light spots, so they are particularly eye-catching. There are many kinds of pots and kettles commonly used in glazed porcelain, and the abdomen is decorated with sky blue or moon white spots, mostly black glaze, and a few are yellow-brown with moon white spots.
At the end of 1960s, glazed porcelain specimens were first discovered at Huangdaoyao site in Jiaxian County, Henan Province. Since 1970s, four producing areas of flower porcelain have been discovered in Lushan, Neixiang, Yuxian and Jiaocheng, Henan. According to the characteristics of glaze color and spots, the glazed porcelain found in these five places can be divided into two categories: one is black or dark brown glaze decorated with moonlight or gray spots, and the utensils are pots, cans and waist drums; The other is black, moonlight or blue glaze, decorated with sky blue pinstripes, and the utensils are pots and cans. The former is found in Ludian and Lushan of Henan, Xiabaiyu, Yuxian and Jiaocheng of Shanxi, and the latter is found in Neixiang of Huangdao and Jiaxian of Henan. Different types of specimens unearthed from five kiln sites are of great help to identify the origin of glazed porcelain in past dynasties.
(VI) Identification of twisted-tire porcelain The so-called twisted-tire porcelain is porcelain clay that is alternately kneaded with white and brown tones, and then the blank is molded to decorate the tire with white and brown lines. This kind of texture is varied, and it can be glazed and fired into twisted tire porcelain. There are cups, bowls, tripods and rectangular pillows unearthed from tombs in Tang Dynasty in Shanxi and Henan provinces. The manufacturing technology of twisted-tire porcelain is much more complicated and difficult than ordinary glazed porcelain, and it is also a new technology in Tang dynasty porcelain. In the Tang Dynasty, a small amount of twisted pottery was also found, but it was only used as a Ming ware, and its craft was rough, which was far less meticulous and regular than twisted porcelain.