Misplaced Pages

#181818

57-573: It spans a total area of about 50,000 square metres (12 acres), with a constructed area of 20,000 square metres (4.9 acres). The museum has a collection of more than 180,000 objects, including items found in the tombs of the Marquis of Dai and his wife, Xin Zhui , in Mawangdui . The museum was closed on 18 June 2012 for renovation and expansion works and reopened on 29 November 2017. The Hunan Museum

114-564: A basaltic rock in Kivu ( Zaïre ), they noted how the occurrence of kaolinite depended on the "degrée de drainage" of the area involved. A clear distinction was found between areas with good drainage (i.e., areas with a marked difference between wet and dry seasons) and those areas with poor drainage (i.e., perennially swampy areas). Kaolinite was only found in the areas with distinct seasonal alternations between wet and dry. The possible significance of alternating wet and dry conditions on

171-608: A sedentary lifestyle , diabetes , angina pectoris , liver disease , and hypertension . Lumbago and a compressed spinal disc probably caused her immense pain, which contributed to a decrease in physical activity. She also suffered from gallstones , one of which lodged in her bile duct and further deteriorated her condition. Her arteries were found to be heavily congested, leading to congestive heart failure . A total of 130 melon seeds were found in Xin Zhui's stomach, intestines, and esophagus; researchers believed she consumed

228-418: A 1:1 or TO clay mineral because its crystals consist of stacked TO layers. Each TO layer consists of a tetrahedral ( T ) sheet composed of silicon and oxygen ions bonded to an octahedral ( O ) sheet composed of oxygen, aluminium, and hydroxyl ions. The T sheet is so called because each silicon ion is surrounded by four oxygen ions forming a tetrahedron. The O sheet is so called because each aluminium ion

285-572: A building area of 91,000 square metres (980,000 sq ft). This article related to a museum in the People's Republic of China is a stub . You can help Misplaced Pages by expanding it . Xin Zhui Xin Zhui ( Chinese : 辛追 ; [ɕín ʈʂwéɪ] ; c.  217 BC –169 or 168 BC), also known as Lady Dai or the Marquise of Dai , was a Chinese noblewoman. She

342-405: A compacted and massive form of kaolin. The chemical formula for kaolinite as written in mineralogy is Al 2 Si 2 O 5 (OH) 4 , however, in ceramics applications the same formula is typically written in terms of oxides, thus giving Al 2 O 3 ·2SiO 2 ·2H 2 O . Compared with other clay minerals, kaolinite is chemically and structurally simple. It is described as

399-417: A lack of convincing results in their own experiments, La Iglesia and Van Oosterwijk-Gastuche (1978) had to conclude, however, that there were other, still unknown, factors involved in the low-temperature nucleation of kaolinite. Because of the observed very slow crystallization rates of kaolinite from solution at room temperature Fripiat and Herbillon (1971) postulated the existence of high activation energies in

456-458: A lavish burial with many artifacts. More than 1,400 precious artifacts were found with Xin Zhui's body including a wardrobe containing 100 silk garments, 182 pieces of expensive lacquerware, makeup and toiletries, ornate burial banners, medicinal products, and 162 carved wooden figurines representing servants and musicians. The fluid present in the coffin allowed Xin Zhui's body to remain in such well-preserved condition. The mysterious liquid she

513-414: A layer structure. From the following equation (as given by Gastuche and DeKimpe, 1962) for kaolinite formation it can be seen that five molecules of water must be removed from the reaction for every molecule of kaolinite formed. Field evidence illustrating the importance of the removal of water from the kaolinite reaction has been supplied by Gastuche and DeKimpe (1962). While studying soil formation on

570-492: A review on the formation of kaolinite, raised the fundamental question how a disordered material (i.e., the amorphous fraction of tropical soils) could ever be transformed into a corresponding ordered structure. This transformation seems to take place in soils without major changes in the environment, in a relatively short period of time, and at ambient temperature (and pressure ). Low-temperature synthesis of clay minerals (with kaolinite as an example) has several aspects. In

627-419: A series of alternations of periodically changing conditions (by definition, taking place in an open system) will bring about the low-temperature formation of more and more of the stable phase kaolinite instead of (ill-defined) amorphous alumino-silicates. In 2009, up to 70% of kaolin was used in the production of paper . Following reduced demand from the paper industry, resulting from both competing minerals and

SECTION 10

#1732771850182

684-516: A variety of imperial foods, including various types of meat, which were reserved for the royal family and members of the ruling class. Most of her clothing was made of silk and other valuable textiles, and she owned many cosmetics. As she aged, Xin Zhui suffered from many ailments that eventually led to a heart attack that caused her death. Along with schistosomiasis , a parasitic infection , she also had coronary thrombosis and arteriosclerosis , most likely linked to excessive weight gained due to

741-596: Is a layered silicate mineral , with one tetrahedral sheet of silica ( SiO 4 ) linked through oxygen atoms to one octahedral sheet of alumina ( AlO 6 ). Kaolinite is a soft, earthy, usually white, mineral (dioctahedral phyllosilicate clay ), produced by the chemical weathering of aluminium silicate minerals like feldspar . It has a low shrink–swell capacity and a low cation-exchange capacity (1–15 meq/100 g). Rocks that are rich in kaolinite, and halloysite , are known as kaolin ( / ˈ k eɪ . ə l ɪ n / ) or china clay . In many parts of

798-510: Is called the "white gold" belt; Sandersville is known as the "Kaolin Capital of the World" due to its abundance of kaolin. In the late 1800s, an active kaolin surface-mining industry existed in the extreme southeast corner of Pennsylvania, near the towns of Landenberg and Kaolin , and in what is present-day White Clay Creek Preserve. The product was brought by train to Newark, Delaware , on

855-407: Is lost. Above around 400 °C hydroxyl ions (OH ) are lost from the kaolinite crystal structure in the form of water: the material cannot now be plasticised by absorbing water. This is irreversible, as are subsequent transformations; this is referred to as calcination . Endothermic dehydration of kaolinite begins at 550–600 °C producing disordered metakaolin , but continuous hydroxyl loss

912-428: Is notable as being one of the most well preserved mummies ever found. Xin Zhui is thought to have lived a wealthy lifestyle. She had private musicians for entertainment who would play for her parties as well as for her personal amusement. She may have enjoyed playing music as well, particularly the guqin , which was traditionally associated with refinement and intellect. As a noble, Xin Zhui also had access to

969-551: Is observed up to 900 °C (1,650 °F). Although historically there was much disagreement concerning the nature of the metakaolin phase, extensive research has led to a general consensus that metakaolin is not a simple mixture of amorphous silica ( SiO 2 ) and alumina ( Al 2 O 3 ), but rather a complex amorphous structure that retains some longer-range order (but not strictly crystalline ) due to stacking of its hexagonal layers. Further heating to 925–950 °C converts metakaolin to an aluminium-silicon spinel which

1026-597: Is one of the most common minerals; it is mined, as kaolin, in Australia , Brazil , Bulgaria , China , Czech Republic , France , Germany , India , Iran , Malaysia , South Africa , South Korea , Spain , Tanzania , Thailand , United Kingdom , United States and Vietnam . Mantles of kaolinite are common in Western and Northern Europe. The ages of these mantles are Mesozoic to Early Cenozoic. Kaolinite clay occurs in abundance in soils that have formed from

1083-400: Is painted with a pattern of stylized clouds and with protective deities and auspicious animals roaming an empty universe. A tiny figure, the deceased woman, is emerging at the bottom center of the head end. Only her upper body is shown, indicating she is about to enter a new world. The third coffin exhibits a different color scheme and iconography. It is shining red, the color of immortality, and

1140-465: Is sometimes also referred to as a gamma-alumina type structure: Upon calcination above 1050 °C, the spinel phase nucleates and transforms to platelet mullite and highly crystalline cristobalite : Finally, at 1400 °C the "needle" form of mullite appears, offering substantial increases in structural strength and heat resistance. This is a structural but not chemical transformation. See stoneware for more information on this form. Kaolinite

1197-760: Is surrounded by six oxygen or hydroxyl ions arranged at the corners of an octahedron. The two sheets in each layer are strongly bonded together via shared oxygen ions, while layers are bonded via hydrogen bonding between oxygen on the outer face of the T sheet of one layer and hydroxyl on the outer face of the O sheet of the next layer. A kaolinite layer has no net electrical charge and so there are no large cations (such as calcium, sodium, or potassium) between layers as with most other clay minerals. This accounts for kaolinite's relatively low ion exchange capacity. The close hydrogen bonding between layers also hinders water molecules from infiltrating between layers, accounting for kaolinite's nonswelling character. When moistened,

SECTION 20

#1732771850182

1254-449: Is that the aluminium cations must be hexacoordinated with respect to oxygen (Caillère and Hénin, 1947; Caillère et al., 1953; Hénin and Robichet, 1955 ). Gastuche et al. (1962) and Caillère and Hénin (1962) have concluded that kaolinite can only ever be formed when the aluminium hydroxide is in the form of gibbsite . Otherwise, the precipitate formed will be a "mixed alumino-silicic gel" (as Millot, 1970, p. 343 put it). If it were

1311-570: The Espluga Freda area of Spain were enriched with kaolinite from a detrital source due to denudation . Difficulties are encountered when trying to explain kaolinite formation under atmospheric conditions by extrapolation of thermodynamic data from the more successful high-temperature syntheses. La Iglesia and Van Oosterwijk-Gastuche (1978) thought that the conditions under which kaolinite will nucleate can be deduced from stability diagrams, based as they are on dissolution data. Because of

1368-609: The Newark-Pomeroy line, along which can still be seen many open-pit clay mines. The deposits were formed between the late Cretaceous and early Paleogene , about 100 to 45 million years ago, in sediments derived from weathered igneous and metakaolin rocks. Kaolin production in the United States during 2011 was 5.5 million tons. During the Paleocene–Eocene Thermal Maximum sediments deposited in

1425-416: The silicic acid must be present in concentrations below the maximum solubility of amorphous silica. The principle behind this prerequisite can be found in structural chemistry: "Since the polysilicate ions are not of uniform size, they cannot arrange themselves along with the metal ions into a regular crystal lattice." (Iler, 1955, p. 182 ) The second aspect of the low-temperature synthesis of kaolinite

1482-555: The Western Han dynasty, elaborate and lavish burials were common practice; it was believed that another world, or afterlife , existed for the dead, and they needed food and accommodation just like the living. Therefore, these necessities in life should be brought into the grave for use in the afterlife. The coffin contained over 150 types of food and drink in total, including grains, vegetables, meats, pastries, and wine. The importance of filial piety during that time also resulted in

1539-414: The body and enter the heavens to become immortal. Xin Zhui's body was remarkably well preserved. Her skin was soft and moist, with muscles that still allowed for her arms and legs to flex at the joints. All her organs and blood vessels were also intact, with small amounts of Type A blood being found in her veins. There was hair on her head, with a wig pinned with a hair clasp on the back of her head. There

1596-460: The chemical weathering of rocks in hot, moist climates ; for example in tropical rainforest areas. Comparing soils along a gradient towards progressively cooler or drier climates, the proportion of kaolinite decreases, while the proportion of other clay minerals such as illite (in cooler climates) or smectite (in drier climates) increases. Such climatically related differences in clay mineral content are often used to infer changes in climates in

1653-549: The contents of Xin Zhui's tomb revealed much information about life in the Han dynasty that was previously unknown. The discovery continues to advance the fields of archaeology and science in the 21st century, particularly in the area of preservation of ancient human remains. Scientists in 2003 developed a "secret compound" that was injected into Xin Zhui's still existing blood vessels to assure her preservation. Her funerary banner had Han dynasty religious art motifs on it. The woman on

1710-413: The daily titrations with hydrochloric acid or sodium hydroxide during at least 60 days will have introduced the necessary element of periodicity. Only now the actual role of what has been described as the "aging" ( Alterung ) of amorphous alumino-silicates (as for example Harder, 1978 had noted) can be fully understood. As such, time is not bringing about any change in a closed system at equilibrium; but

1767-443: The decorative motifs include divine animals and a winged immortal flanking three-peaked Mount Kunlun, which is a prime symbol of eternal happiness. Inside this tomb on top of the fourth and innermost coffin, the excavators found a painted silk banner about two meters long. Yellow and black feathers are stuck on the cover board of the coffin. The feathers stuck to the coffin were expressing the hopes that Xin Zhui would grow feathers on

Hunan Museum - Misplaced Pages Continue

1824-513: The effect of digital media, in 2016 the market share was reported to be: paper, 36%; ceramics, 31%; paint, 7% and other, 26%. According to the USGS , in 2021 the global production of kaolin was estimated to be around 45 million tonnes. Global production of kaolin by country in 2012 was estimated to be: Some selected typical properties of various ceramic grade kaolins are: Kaolin is generally recognized as safe , but may cause mild irritation of

1881-451: The first place the silicic acid to be supplied to the growing crystal must be in a monomeric form, i.e., silica should be present in very dilute solution (Caillère et al., 1957; Caillère and Hénin, 1960; Wey and Siffert, 1962; Millot, 1970 ). In order to prevent the formation of amorphous silica gels precipitating from supersaturated solutions without reacting with the aluminium or magnesium cations to form crystalline silicates ,

1938-608: The geological past, where ancient soils have been buried and preserved. In the Institut National pour l'Étude Agronomique au Congo Belge (INEAC) classification system, soils in which the clay fraction is predominantly kaolinite are called kaolisol (from kaolin and soil). In the United States, the main kaolin deposits are found in central Georgia , on a stretch of the Atlantic Seaboard fall line between Augusta and Macon . This area of thirteen counties

1995-405: The low-temperature nucleation of kaolinite. At high temperatures, equilibrium thermodynamic models appear to be satisfactory for the description of kaolinite dissolution and nucleation , because the thermal energy suffices to overcome the energy barriers involved in the nucleation process. The importance of syntheses at ambient temperature and atmospheric pressure towards the understanding of

2052-415: The mechanism involved in the nucleation of clay minerals lies in overcoming these energy barriers. As indicated by Caillère and Hénin (1960) the processes involved will have to be studied in well-defined experiments, because it is virtually impossible to isolate the factors involved by mere deduction from complex natural physico-chemical systems such as the soil environment. Fripiat and Herbillon (1971), in

2109-421: The melon very quickly. From this, researchers inferred that she died in summer, when fruits and melons ripen. The presence of melon seeds in her stomach also indicates that she died within two to three hours of eating the fruit. Xin Zhui died at approximately 50 years of age in 169 or 168 BC. In 1968, workers digging an air raid shelter for a hospital near Changsha unearthed the tomb of Xin Zhui, as well as

2166-441: The only requirement, large amounts of kaolinite could be harvested simply by adding gibbsite powder to a silica solution. Undoubtedly a marked degree of adsorption of the silica in solution by the gibbsite surfaces will take place, but, as stated before, mere adsorption does not create the layer lattice typical of kaolinite crystals. The third aspect is that these two initial components must be incorporated into one mixed crystal with

2223-418: The plates hydrogen bond directly to each other, so that the dried clay is rigid but still fragile. If the clay is moistened again, it will once more become plastic. Kaolinite group clays undergo a series of phase transformations upon thermal treatment in air at atmospheric pressure. High-energy milling of kaolin results in the formation of a mechanochemically amorphized phase similar to metakaolin , although

2280-432: The properties of this solid are quite different. The high-energy milling process is highly inefficient and consumes a large amount of energy. Below 100 °C, exposure to low humidity air will result in the slow evaporation of any liquid water in the kaolin. At low moisture content the mass can be described leather dry , and at near 0% moisture it is referred to as bone dry . Above 100 °C any remaining free water

2337-413: The role of periodicity becomes convincingly clear. DeKimpe et al. (1961) had used daily additions of alumina (as AlCl 3 ·6 H 2 O ) and silica (in the form of ethyl silicate ) during at least two months. In addition, adjustments of the pH took place every day by way of adding either hydrochloric acid or sodium hydroxide . Such daily additions of Si and Al to the solution in combination with

Hunan Museum - Misplaced Pages Continue

2394-650: The same conditions failed to preserve other bodies. Other " Mawangdui -Type" cadavers in similar conditions have been found in China. Two from the same time period as Xin Zhui; they belong to a male official named Sui Xiaoyuan  [ zh ] found in Jingzhou and a noblewoman named Ling Huiping  [ zh ] found in Lianyungang . No consistent pattern explained why their bodies were preserved. All three had coffins containing liquid. However, Lady Dai's

2451-580: The skin or mucous membranes. Kaolin products may also contain traces of crystalline silica , a known carcinogen if inhaled. In the US, the Occupational Safety and Health Administration (OSHA) has set the legal limit ( permissible exposure limit ) for kaolin exposure in the workplace as 15 mg/m total exposure and 5 mg/m respiratory exposure over an 8-hour workday. The National Institute for Occupational Safety and Health (NIOSH) has set

2508-421: The tiny platelike crystals of kaolinite acquire a layer of water molecules that cause crystals to adhere to each other and give kaolin clay its cohesiveness. The bonds are weak enough to allow the plates to slip past each other when the clay is being molded, but strong enough to hold the plates in place and allow the molded clay to retain its shape. When the clay is dried, most of the water molecules are removed, and

2565-410: The tomb of Xin Zhui, four coffins of decreasing sizes enclose one another. The first and outermost coffin is painted black, the color of death and the underworld. All painted images sealed inside this coffin were thus designed not for an outside viewer but for the deceased and concern the themes of death and rebirth, protection in the afterlife, and immortality. The second coffin has a black background but

2622-521: The tombs of her husband and a young man who is most commonly thought to be her son. With the assistance of over 1,500 local high school students, archaeologists began a large excavation of the site beginning in January 1972. Xin Zhui's body was found within four rectangular pine constructs that sat inside one another which were buried beneath layers of charcoal and white clay . The corpse was wrapped in twenty layers of clothing bound with silk ribbons. In

2679-427: The top is possibly Xin Zhui herself drawn in imitation of Nüwa or the snake-like spirits next to her who could have been inspired by Nüwa, in the process of becoming a xian . Kaolinite Kaolinite ( / ˈ k eɪ . ə l ə ˌ n aɪ t , - l ɪ -/ KAY -ə-lə-nyte, -⁠lih- ; also called kaolin ) is a clay mineral , with the chemical composition Al 2 Si 2 O 5 ( OH ) 4 . It

2736-864: The transition of allophane into kaolinite has been stressed by Tamura and Jackson (1953). The role of alternations between wetting and drying on the formation of kaolinite has also been noted by Moore (1964). Syntheses of kaolinite at high temperatures (more than 100 °C [212 °F]) are relatively well known. There are for example the syntheses of Van Nieuwenberg and Pieters (1929); Noll (1934); Noll (1936); Norton (1939); Roy and Osborn (1954); Roy (1961); Hawkins and Roy (1962); Tomura et al. (1985); Satokawa et al. (1994) and Huertas et al. (1999). Relatively few low-temperature syntheses have become known (cf. Brindley and DeKimpe (1961); DeKimpe (1969); Bogatyrev et al. (1997) ). Laboratory syntheses of kaolinite at room temperature and atmospheric pressure have been described by DeKimpe et al. (1961). From those tests

2793-588: The village had become the main source of Jingdezhen's kaolin over the course of the Qing dynasty . The mineralogical suffix -ite was later added to generalize the name to cover nearly identical minerals from other locations. Kaolinite is also occasionally discussed under the archaic names lithomarge and lithomarga from Latin lithomarga , a combination of litho- ( ‹See Tfd› Greek : λίθος ， líthos , "stone") and marga (" marl "). In more proper modern use, lithomarge now refers specifically to

2850-584: The world kaolin is colored pink-orange-red by iron oxide , giving it a distinct rust hue. Lower concentrations of iron oxide yield the white, yellow, or light orange colors of kaolin. Alternating lighter and darker layers are sometimes found, as at Providence Canyon State Park in Georgia, United States. Kaolin is an important raw material in many industries and applications. Commercial grades of kaolin are supplied and transported as powder, lumps, semi-dried noodle or slurry . Global production of kaolin in 2021

2907-444: Was acidic, whereas others' were alkaline, which would have aided bacterial growth. The tombs were also dug to different depths, from 5 metres (16 feet) to 16 metres (52 feet) and contained differing amounts of charcoal and white clay. In addition, similar airtight and watertight coffins failed to keep other cadavers from decomposing into skeletons or dust. Besides having some of the best preserved human remains ever discovered in China,

SECTION 50

#1732771850182

2964-644: Was estimated to be 45 million tonnes, with a total market value of US $ 4.24 billion. The English name kaolin was borrowed in 1727 from François Xavier d'Entrecolles 's 1712 French reports on the manufacture of Jingdezhen porcelain . D'Entrecolles was transcribing the Chinese term 高嶺土 , now romanized as gāolǐngtǔ in pinyin , taken from the name of the village of Gaoling ("High Ridge") near Ehu in Fuliang County , now part of Jiangxi Province 's Jingdezhen Prefecture . The area around

3021-545: Was first built in 1951 and opened to the public in July 1956. On June 18, 2012, the museum closed its doors to the public due to reconstruction. China Central Academy of Fine Arts , assisted by Japanese architect Arata Isozaki , designed the present building. The construction began in 2012 and the museum was completed in 2017. The museum was reopened to the general public on November 29, 2017. The new building covers approximately 49,000 square metres (530,000 sq ft), with

3078-517: Was skin on her face, and her eyelashes and nose hair remained intact. The tympanic membrane of her left ear was also intact, and her finger and toe prints were distinct. This preservation allowed doctors at Hunan Provincial Medical Institute to perform an autopsy on 14 December 1972. Much of what is known about Xin Zhui's lifestyle was derived from this and other examinations. As a member of the nobility, her body would have been washed with fragrant water and wine, which has antibacterial properties. In

3135-529: Was soaked in was acidic, which may have worked to preserve the body by preventing bacteria from growing. Tests revealed it to also contain salt and magnesium. Many scientists believe that the fluid stemmed from the body, rather than liquid poured into the coffin. When the autopsy on Xin Zhui's remains was done, contact with the fluid caused a rash on the hands of the scientists conducting it. The rash persisted on their skin for three months. Scientists believe that three major factors helped preserve her body. First

3192-450: Was the careful preparation of the body for burial, which slowed early stage of decomposition. Second, the body was placed in an airtight set of coffins. Lastly, the burial chamber was positioned deep underground, surrounded by charcoal and white clay. Water and air did not leak in and the temperature stayed constantly cool. However, scientists do not know for certain what combination of factors helped preserve Xin Zhui's corpse, or why almost

3249-699: Was the wife of Li Cang ( 利蒼 ), the Marquis of Dai, and Chancellor of the Changsha Kingdom , during the Western Han dynasty of ancient China. Her tomb, containing her well-preserved remains and 1,400 artifacts, was discovered in 1971 at Mawangdui , Changsha , Hunan, China. Her body and belongings are currently under the care of the Hunan Museum ; artifacts from her tomb were displayed in Santa Barbara and New York City in 2009. Her body

#181818