1.
Japanese sword mountings
–
Japanese sword mountings are the various housings and associated fittings that hold the blade of a Japanese sword when it is being worn or stored. Fuchi, The fuchi is a hilt collar between the tsuka and the tsuba. Habaki, The habaki is a shaped metal collar used to keep the sword from falling out of the saya and to support the fittings below. Kaeshizuno - a hook shaped fitting used to lock the saya to the obi while drawing, kashira, The kashira is a butt cap on the end of the tsuka. Kōgai, The kōgai is a spike for hair arranging carried sometimes as part of Katana-Koshirae in another pocket, koiguchi, The koiguchi is the mouth of the saya or its fitting, traditionally made of buffalo horn. Kojiri, The kojiri is the end of the saya or the protective fitting at the end of the saya, kozuka, The kozuka is a decorative handle fitting for the kogatana, a small utility knife fit into a pocket on the saya. Kuri-kata, The kuri-kata is a knob on the side of the saya for attaching the sageo, mekugi, The mekugi is a small peg for securing the tsuka to the nakago. Menuki, The menuki are ornaments on the tsuka, to fit into the palm for grip, mekugi-ana, The mekugi-ana are the holes in the tsuka and nakago for the mekugi. Sageo, The sageo is the used to tie saya to the belt/obi when worn. Same-hada - literally the pattern of the ray skin, same-kawa, same-kawa is the ray or shark skin wrapping of the tsuka. Saya, The saya is a wooden scabbard for the blade, seppa, The seppa are washers above and below the tsuba to tighten the fittings. Shitodome - an accent on the kurikata for aesthetic purposes, often done in metal in modern reproductions. Tsuba, The tsuba is a hand guard, tsuka, The tsuka is the hilt or handle, made of wood and wrapped in samegawa. Tsuka-maki - the art of wrapping the tsuka, including the most common hineri maki, Tsuka-ito, Tsuka-ito the wrap of the tsuka, traditionally silk but today most often in cotton and sometimes leather. Wari-bashi - metal chop-sticks fit in a pocket on the saya and they were externally featureless save for the needed mekugi-ana to secure the nakago, though sometimes sayagaki was also present. The need for specialized storage is because prolonged koshirae mounting harmed the blade, owing to such as the lacquered wood retaining moisture. Such mountings are not intended for combat, as the lack of a tsuba and proper handle wrappings were deleterious. However, there have been loosely similar hidden mountings, such as the shikomizue, the word koshirae is derived from the verb koshiraeru, which is no longer used in current speech
2.
Walters Art Museum
–
The Walters Art Museum, located in Mount Vernon-Belvedere, Baltimore, Maryland, is a public art museum founded and opened in 1934. It holds collections established during the mid-19th Century, located across the back alley, a block south of the Walters mansion on West Monument Street/Mount Vernon Place, on the northwest corner of North Charles Street at West Centre Street. The following year, The Walters reopened its original building after a dramatic three-year physical renovation and replacement of internal utilities. The Archimedes Palimpsest was on loan to the Walters Art Museum from a collector for conservation. This was one of the largest and most comprehensive such releases made by any museum, the Walters collection of ancient art includes examples from Egypt, Nubia, Greece, Rome, Etruria and the Near East. In 1911, Henry Walters purchased almost 100 gold artifacts from the Chiriqui region of western Panama in Central America, the museum owns the oldest surviving Chinese wood-and-lacquer image of the Buddha. It is exhibited in a gallery dedicated solely to this work, the Museum holds one of the largest and finest collections of Thai bronze, scrolls, and banner paintings in the world. Islamic art in all media is represented at the Walters, the Walters Museum owns an array of Islamic manuscripts. Walters Art Museum, MS W.613 contains five Mughal miniatures from a very important Khamsa of Nizami made for the Emperor Akbar, Henry Walters assembled a collection of art produced during the Middle Ages in all the major artistic media of the period. This forms the basis of the Walters medieval collection, for which the Museum is best known internationally. Considered one of the best collections of art in the United States, the Museums holdings include examples of metalwork, sculpture, stained glass, textiles, icons. Sculpted heads from the royal Abbey of St. Denis are rare surviving examples of sculptures that are directly connected with the origins of Gothic art in 12th Century France. An ivory casket covered with scenes of jousting knights is one of about a dozen such objects to survive in the world, many of these works are on display in the Museums galleries. Works in the collection are the subject of active research by the curatorial and conservation departments of the museum. The collection of European Renaissance and Baroque art features holdings of paintings, sculpture, furniture, ceramics, metal work, arms, the museum has one of ten surviving examples of the Sèvres pot-pourri vase in the shape of a ship from the 1750s and 1760s. William and Henry Walters collected works by late 19th Century French academic masters, Henry Walters was particularly interested in the courtly arts of 18th Century France. The museum’s collection of Sèvres porcelain includes a number of pieces that were made for members of the Royal Bourbon Court at Versailles Palace outside of Paris. Portrait miniatures and the examples of works, especially snuffboxes and watches, are displayed in the Treasury, along with some exceptional 19th-
3.
Japan
–
Japan is a sovereign island nation in Eastern Asia. Located in the Pacific Ocean, it lies off the eastern coast of the Asia Mainland and stretches from the Sea of Okhotsk in the north to the East China Sea, the kanji that make up Japans name mean sun origin. 日 can be read as ni and means sun while 本 can be read as hon, or pon, Japan is often referred to by the famous epithet Land of the Rising Sun in reference to its Japanese name. Japan is an archipelago consisting of about 6,852 islands. The four largest are Honshu, Hokkaido, Kyushu and Shikoku, the country is divided into 47 prefectures in eight regions. Hokkaido being the northernmost prefecture and Okinawa being the southernmost one, the population of 127 million is the worlds tenth largest. Japanese people make up 98. 5% of Japans total population, approximately 9.1 million people live in the city of Tokyo, the capital of Japan. Archaeological research indicates that Japan was inhabited as early as the Upper Paleolithic period, the first written mention of Japan is in Chinese history texts from the 1st century AD. Influence from other regions, mainly China, followed by periods of isolation, from the 12th century until 1868, Japan was ruled by successive feudal military shoguns who ruled in the name of the Emperor. Japan entered into a period of isolation in the early 17th century. The Second Sino-Japanese War of 1937 expanded into part of World War II in 1941, which came to an end in 1945 following the bombings of Hiroshima and Nagasaki. Japan is a member of the UN, the OECD, the G7, the G8, the country has the worlds third-largest economy by nominal GDP and the worlds fourth-largest economy by purchasing power parity. It is also the worlds fourth-largest exporter and fourth-largest importer, although Japan has officially renounced its right to declare war, it maintains a modern military with the worlds eighth-largest military budget, used for self-defense and peacekeeping roles. Japan is a country with a very high standard of living. Its population enjoys the highest life expectancy and the third lowest infant mortality rate in the world, in ancient China, Japan was called Wo 倭. It was mentioned in the third century Chinese historical text Records of the Three Kingdoms in the section for the Wei kingdom, Wa became disliked because it has the connotation of the character 矮, meaning dwarf. The 倭 kanji has been replaced with the homophone Wa, meaning harmony, the Japanese word for Japan is 日本, which is pronounced Nippon or Nihon and literally means the origin of the sun. The earliest record of the name Nihon appears in the Chinese historical records of the Tang dynasty, at the start of the seventh century, a delegation from Japan introduced their country as Nihon
4.
Japanese sword
–
A Japanese sword is one of several types of traditionally made swords from Japan. Some of the commonly known types of Japanese swords are the katana, wakizashi. The type classifications for Japanese swords indicate the combination of a blade and its mounts as this, then, an unsigned and shortened blade that was once made and intended for use as a tachi may be alternately mounted in tachi koshirae and katana koshirae. It is properly distinguished, then, by the style of mount it currently inhabits, the following are types of Japanese swords, Chokutō, A straight single edged sword that was produced prior to the 10th century, and without differential hardening or folding. Tsurugi/Ken, A straight two edged sword that was produced prior to the 10th century, and may be without differential hardening or folding. Tachi, A sword that is longer and more curved than the later katana, with curvature centered from the middle or towards the tang. Tachi were worn suspended, with the edge downward, the tachi was in vogue before the 15th century. Kodachi, A shorter version of the tachi, but with similar mounts and intended use, Ōdachi /Nodachi, Very large tachi, some in excess of 100 cm, and usually a blade of the late 14th century. Uchigatana, A development from the tachi in the 15th century, worn with the edge upwards in the obi. Katate-uchi, A short type of uchigatana developed in the 16th century, with short tang, one of the forerunners of the wakizashi. Katana, A general term for the sword with a curved blade longer than 60 cm. Developed from the uchigatana and the sword of the class of the Edo period. Wakizashi, A general term for a sword between one and two long, predominantly made after 1600. The name refers to the style of mount as well as a type which means that a naginata blade could be mounted in a nagamaki mount. Naginata, A polearm with a curved single-edged blade, naginata mounts consist of a long wooden pole, different from a nagamaki mount, which is shorter and wrapped. Yari, A spear, or spear-like polearm, the main blade is symmetric and straight unlike a naginata, and usually smaller but can be as large or bigger than some naginata blades. Usually one-edged, but some were double-edged, though asymmetrical, ken, Usually a tanto or wakizashi length religious or ceremonial blade, with a gentle leaf shape and point, but some may be larger and can also refer to old pre-curve types of swords as above. Arrowheads for war, yajiri, were made using the same methods as Japanese swords were
5.
Akita Prefecture
–
Akita Prefecture is a prefecture of Japan located in the Tōhoku region of northern Honshu, the main island of Japan. The capital is the city of Akita, the area of Akita has been created from the ancient provinces of Dewa and Mutsu. Akita was a region of hunter-gatherers and principally nomadic tribes, the first historical record of what is now Akita Prefecture dates to 658, when the Abe no Hirafu conquered the native Ezo tribes at what are now the cities of Akita and Noshiro. Hirafu, then governor of Koshi Province, established a fort on the Mogami River, in 733, a new military settlement—later renamed Akita Castle—was built in modern-day Akita city at Takashimizu, and more permanent roads and structures were developed. The region was used as a base of operations for the Japanese empire as it drove the native Ezo people from northern Honshū. During the Tokugawa shogunate it was appropriated to the Satake clan, throughout this period, it was classified as part of Dewa Province. In 1871, during the Meiji Restoration, Dewa Province was reshaped, the famous Heian period waka poet, Ono no Komachi, is said to have been born in Yuzawa City, Ogachi Town, located in the southeast of the prefecture. Akita Prefecture is rectangular in shape, roughly 181 km from north to south and 111 km from west to east, the Ōu Mountains mark the eastern border of the prefecture, and the higher Dewa Mountains run parallel through the center of the prefecture. Like much of northern Japan, the prefecture has cold winters, the Oga Peninsula is a prominent feature of the coastline. This has led many people to migrate to Tokyo and other large cities. Akita Prefecture is where declines in population are most severe in Japan and it also has the lowest number of children as a percentage of the population, at 11. 2%. As of 2010, it has a population of just over 1 million people, Akita is famous for rice farming and its sake breweries. It is well known for having the highest consumption of sake in Japan, the women of the region, referred to as Akita bijin, have also gained widespread renown for their white skin, rounded faces and high voices, all of which are considered highly desirable. Ono no Komachi is an example of an Akita bijin. Kiritanpo Nabe Gakko Rice – Akita komachi Sake Near Lake Tazawa and these are popular with tourists from all over Japan. In addition, its numerous seasonal festivals offer a glimpse of rural or traditional Japan, some famous examples are the Akita Kantō, the Omagari Fireworks, Namahage Festival, and the Yokote Kamakura Festivals. Kakunodate is a charming old town, known as the little Kyoto. The Aoyagi house is the residence of Odano Naotake, the man who illustrated Japans first modern guide to the human anatomy
6.
Lacquerware
–
Lacquerware are objects decoratively covered with lacquer, the treated, dyed and dried sap of Toxicodendron vernicifluum or related trees, applied in several coats to a base that is usually wood. This dries to a hard and smooth surface layer which is durable, waterproof. Lacquer is sometimes painted with pictures, inlaid with shell and other materials, or carved, as well as dusted with gold and given other further decorative treatments. Lacquerware includes small or large containers, tableware, a variety of objects carried by people. Most East Asian countries have traditions of lacquer work, going back several thousand years in the cases of China. True lacquer is not made outside Asia, but some imitations, such as Japanning in Europe, or parallel techniques, various prehistoric lacquerwares have been unearthed in China dating back to the Neolithic period and objects with lacquer coating found in Japan dating to the late Jōmon period. The earliest known object, a red wooden bowl, was unearthed at a Hemudu culture site in Zhejiang. During the Shang dynasty of China, sophisticated lacquer process techniques developed became an artistic craft. During the Eastern Zhou period, lacquerware began appearing in large quantity and this is the earliest era from which notable quantities of lacquerware have survived. By the Han dynasty, special administrations were established to organize, elaborate incised decorations were used in lacquerware during the Han dynasty. In the Tang dynasty, Chinese lacquerware saw a new style marked by the use of sheets of gold or silver made in shapes, such as birds, animals. This was done by a known as pingtuo. Such techniques were time-consuming and costly, but these lacquerware were considered highly refined and it was also the period when the earliest practice of carving lacquerware began. The art of gold, silver, and mother-of-pearl continued from the Tang into the Song dynasty. Several existing decorative techniques gradually developed further after the 10th century, such as qiangjin, diaotian or tianqi, especially the art of inlaying lacquer with mother-of-pearl was intensively developed during the Song dynasty. However, during the Song, the craft also made use of inlaid gold in a process of which is to engrave intricate patterns in the lacquer surface. The knowledge of the Chinese methods of the process spread from China during the Han, Tang and Song dynasties, eventually it was introduced to Korea, Japan, Southeast. One of the earliest Japanese techniques for decorating the lacquer surface was, besides painting simple designs and this technique was transmitted from China during the Tang dynasty
7.
Katana
–
Historically, katana were one of the traditionally made Japanese swords that were used by the samurai of ancient and feudal Japan. The katana is characterized by its appearance, a curved, single-edged blade with a circular or squared guard. These references to uchigatana and tsubagatana seem to indicate a different style of sword, the Mongol invasions of Japan faciliated a change in the designs of Japanese swords. Thin tachi and chokuto style blades were often unable to cut through the boiled leather armour of the Mongols, the evolution of the tachi into what would become the katana seems to have continued during the early Muromachi period. Starting around the year 1400, long swords signed with the signature were made. This was in response to samurai wearing their tachi in what is now called katana style, Japanese swords are traditionally worn with the signature facing away from the wearer. When a tachi was worn in the style of a katana, with the cutting edge up, the fact that swordsmiths started signing swords with a katana signature shows that some samurai of that time period had started wearing their swords in a different manner. The rise in popularity of katana amongst samurai came about due to the nature of close-combat warfare. The quicker draw of the sword was well suited to combat where victory depended heavily on short response times, the katana further facilitated this by being worn thrust through a belt-like sash with the sharpened edge facing up. Ideally, samurai could draw the sword and strike the enemy in a single motion, previously, the curved tachi had been worn with the edge of the blade facing down and suspended from a belt. The length of the katana blade varied considerably during the course of its history, in the late 14th and early 15th centuries, katana blades tended to have lengths between 70 and 73 centimetres. During the early 16th century, the average length dropped about 10 centimetres, by the late 16th century, the average length had increased again by about 13 centimetres, returning to approximately 73 centimetres. The katana was often paired with a smaller companion sword, such as a wakizashi, or it could also be worn with the tantō. The pairing of a katana with a sword is called the daishō. Only samurai could wear the daisho, it represented the social power, during the Meiji period, the samurai class was gradually disbanded, and the special privileges granted to them were taken away including the right to carry swords in public. The Haitōrei Edict in 1876 forbade the carrying of swords in public except for individuals, such as former samurai lords, the military. Skilled swordsmiths had trouble making a living during this period as Japan modernized its military, and many swordsmiths started making other items, such as equipment, tools. Military action by Japan in China and Russia during the Meiji period helped revive interest in swords, Japanese military swords produced between 1875 and 1945 are referred to as guntō
8.
Meiji Restoration
–
The Meiji Restoration, also known as the Meiji Ishin, Renovation, Revolution, Reform, or Renewal, was an event of change that restored practical imperial rule to Japan in 1868 under Emperor Meiji. Although there were Emperors before the Meiji Restoration, the events restored practical abilities, Meiji government also made education compulsory for both boys and girls at minimal fees. The goals of the government were expressed by the new emperor in the Charter Oath. The Restoration led to changes in Japans political and social structure. In Japan however, unlike China, foreign ideas were not associated with opium addiction. Figures like Shimazu Nariakira concluded that if we take the initiative, we can dominate, if we do not, we will be dominated, leading Japan to throw open its doors to foreign technology. Observing Japans response to the powers, Li Hongzhang considered Japan Chinas principal security threat as early as 1863. The word Meiji means enlightened rule and the goal was to modern advances with traditional eastern values. The main leaders of this were Itō Hirobumi, Matsukata Masayoshi, Kido Takayoshi, Itagaki Taisuke, Yamagata Aritomo, Mori Arinori, Ōkubo Toshimichi, and Yamaguchi Naoyoshi. The foundation of the Meiji restoration was the 1866 Satsuma-Chōshū Alliance between Saigō Takamori and Kido Takayoshi, leaders of the reformist elements in the Satsuma Domain and Chōshū Domain. These two leaders supported the Emperor Kōmei and were brought together by Sakamoto Ryōma for the purpose of challenging the ruling Tokugawa shogunate, after Emperor Kōmeis death on January 30,1867, Emperor Meiji ascended the throne on February 3. This period also saw Japan change from being a society to having a market economy. The Tokugawa Shogunate came to its end on November 9,1867, when Tokugawa Yoshinobu. Shortly thereafter in January 1868, the Boshin War started with the Battle of Toba–Fushimi in which Chōshū and this forced the Emperor to strip Yoshinobu of all power, setting the stage for official restoration. We shall henceforward exercise supreme authority in all the internal and external affairs of the country, consequently the title of Emperor must be substituted for that of Taikun, in which the treaties have been made. Officers are being appointed by us to the conduct of foreign affairs and it is desirable that the representatives of the treaty powers recognize this announcement. All Tokugawa lands were seized and placed under control, thus placing them under the prerogative of the new Meiji government. With Fuhanken sanchisei, the areas were split into three types, urban prefectures, rural prefectures and the already existing domains
9.
Tiffany & Co.
–
Tiffany & Company is an American luxury jewelry and specialty retailer, headquartered in New York City. Tiffany sells jewelry, sterling silver, china, crystal, stationery, fragrances, water bottles, watches, personal accessories, many of these goods are sold at Tiffany stores, as well as through direct-mail and corporate merchandising. Tiffany is renowned for its goods and is particularly known for its diamond jewelry. Tiffany markets itself as an arbiter of taste and style, and was once a purveyor to the Russian imperial family, founded by Charles Lewis Tiffany and John B. The name was shortened to Tiffany & Company in 1853 when Charles Tiffany took control, Tiffany & Company has since opened stores in major cities all over the world. Unlike other stores at the time in the 1830s, Tiffany clearly marked the prices on its goods to forestall any haggling over prices, in addition, against the social norm at the time, Tiffany only accepted cash payments, and did not accept payments on credit. Such practices, fixed prices for ready money, were first introduced by Palmers of London Bridge in 1750, who employed the young Robert Owen, the later social reformer. The first Tiffanys mail order catalog, known as the Blue Book, was published in 1845 in the United States, in 1862, Tiffany & Company supplied the Union Army with swords, flags and surgical implements. In 1867, Tiffany & Co. was the first US firm to win an award for the excellence in silverware at the Exposition Universelle in Paris. In 1870, the built an new store building at 15 Union Square West, Manhattan, designed by John Kellum. It was described by The New York Times as a palace of jewels, Tiffany stayed at this site until 1906. In 1877, an insignia that would become the famous New York Yankees NY logo was struck on a medal of honor by Tiffany & Company. In 1878, Tiffany won the medal for jewelry and a grand prize for silverware at the Paris Exposition. In 1887, Tiffany bought the French Crown Jewels, which attracted publicity, the company revised the Great Seal of the United States in 1885. In 1902, after the death of Charles Lewis Tiffany, his son, Louis Comfort Tiffany, in 1919, the company made a revision to the Medal of Honor on behalf of the United States Department of the Navy. This Tiffany Cross version was rare because it was awarded only for combat, in 1942 the Navy established the Tiffany version for non-combat heroism, but in August 1942 the Navy eliminated the Tiffany Cross and the two-medal system. In 1956, legendary designer Jean Schlumberger joined Tiffany, and Andy Warhol collaborated with Tiffany to create Tiffany Holiday Cards. In 1968 Lady Bird Johnson, First Lady of the U. S. at the time, in November 1978, Tiffany & Co. was sold to Avon Products Inc. for about US$104 million in stock
10.
Titanium
–
Titanium is a chemical element with symbol Ti and atomic number 22. It is a transition metal with a silver color, low density. Titanium is resistant to corrosion in sea water, aqua regia, titanium was discovered in Cornwall, Great Britain, by William Gregor in 1791, and it is named by Martin Heinrich Klaproth for the Titans of Greek mythology. The metal is extracted from its principal mineral ores by the Kroll, the most common compound, titanium dioxide, is a popular photocatalyst and is used in the manufacture of white pigments. Other compounds include titanium tetrachloride, a component of smoke screens and catalysts, and titanium trichloride, the two most useful properties of the metal are corrosion resistance and strength-to-density ratio, the highest of any metallic element. In its unalloyed condition, titanium is as strong as some steels, there are two allotropic forms and five naturally occurring isotopes of this element, 46Ti through 50Ti, with 48Ti being the most abundant. Although they have the number of valence electrons and are in the same group in the periodic table. As a metal, titanium is recognized for its high strength-to-weight ratio and it is a strong metal with low density that is quite ductile, lustrous, and metallic-white in color. The relatively high melting point makes it useful as a refractory metal and it is paramagnetic and has fairly low electrical and thermal conductivity. Commercial grades of titanium have ultimate tensile strength of about 434 MPa, equal to that of common, low-grade steel alloys, titanium is 60% denser than aluminium, but more than twice as strong as the most commonly used 6061-T6 aluminium alloy. Certain titanium alloys achieve tensile strengths of over 1400 MPa, however, titanium loses strength when heated above 430 °C. Titanium is not as hard as some grades of heat-treated steel, it is non-magnetic, machining requires precautions, because the material might gall unless sharp tools and proper cooling methods are used. Like steel structures, those made from titanium have a limit that guarantees longevity in some applications. The metal is an allotrope of an hexagonal α form that changes into a body-centered cubic β form at 882 °C. The specific heat of the α form increases dramatically as it is heated to this transition temperature but then falls, similar to zirconium and hafnium, an additional omega phase exists, which is thermodynamically stable at high pressures, but metastable at ambient pressures. This phase is usually hexagonal or trigonal and can be considered to be due to a soft longitudinal acoustic phonon of the β phase causing collapse of planes of atoms, like aluminium and magnesium, titanium metal and its alloys oxidize immediately upon exposure to air. Titanium readily reacts with oxygen at 1,200 °C in air and it is, however, slow to react with water and air at ambient temperatures because it forms a passive oxide coating that protects the bulk metal from further oxidation. When it first forms, this layer is only 1–2 nm thick but continues to grow slowly
11.
Platinum
–
Platinum is a chemical element with symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious and its name is derived from the Spanish term platina, translated into little silver. Platinum is a member of the group of elements and group 10 of the periodic table of elements. It has six naturally occurring isotopes and it is one of the rarer elements in Earths crust with an average abundance of approximately 5 μg/kg. It occurs in some nickel and copper ores along with some deposits, mostly in South Africa. Because of its scarcity in Earths crust, only a few hundred tonnes are produced annually, Platinum is one of the least reactive metals. It has remarkable resistance to corrosion, even at high temperatures, consequently, platinum is often found chemically uncombined as native platinum. Because it occurs naturally in the sands of various rivers. Platinum is used in catalytic converters, laboratory equipment, electrical contacts and electrodes, platinum resistance thermometers, dentistry equipment, and jewelry. Being a heavy metal, it leads to health issues upon exposure to its salts, compounds containing platinum, such as cisplatin, oxaliplatin and carboplatin, are applied in chemotherapy against certain types of cancer. Pure platinum is a lustrous, ductile, and malleable, silver-white metal, Platinum is more ductile than gold, silver or copper, thus being the most ductile of pure metals, but it is less malleable than gold. The metal has excellent resistance to corrosion, is stable at temperatures and has stable electrical properties. Platinum reacts with oxygen slowly at high temperatures. It reacts vigorously with fluorine at 500 °C to form platinum tetrafluoride and it is also attacked by chlorine, bromine, iodine, and sulfur. Platinum is insoluble in hydrochloric and nitric acid, but dissolves in hot aqua regia to form chloroplatinic acid and its physical characteristics and chemical stability make it useful for industrial applications. Its resistance to wear and tarnish is well suited to use in fine jewelry, the most common oxidation states of platinum are +2 and +4. The +1 and +3 oxidation states are common, and are often stabilized by metal bonding in bimetallic species. As is expected, tetracoordinate platinum compounds tend to adopt 16-electron square planar geometries, Platinum has six naturally occurring isotopes, 190Pt, 192Pt, 194Pt, 195Pt, 196Pt, and 198Pt
12.
Iron
–
Iron is a chemical element with symbol Fe and atomic number 26. It is a metal in the first transition series and it is by mass the most common element on Earth, forming much of Earths outer and inner core. It is the fourth most common element in the Earths crust, like the other group 8 elements, ruthenium and osmium, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen, fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history. Pure iron is soft, but is unobtainable by smelting because it is significantly hardened and strengthened by impurities, in particular carbon. A certain proportion of carbon steel, which may be up to 1000 times harder than pure iron. Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, further refinement with oxygen reduces the carbon content to the correct proportion to make steel. Steels and iron alloys formed with metals are by far the most common industrial metals because they have a great range of desirable properties. Iron chemical compounds have many uses, Iron oxide mixed with aluminium powder can be ignited to create a thermite reaction, used in welding and purifying ores. Iron forms binary compounds with the halogens and the chalcogens, among its organometallic compounds is ferrocene, the first sandwich compound discovered. Iron plays an important role in biology, forming complexes with oxygen in hemoglobin and myoglobin. Iron is also the metal at the site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants. A human male of average height has about 4 grams of iron in his body and this iron is distributed throughout the body in hemoglobin, tissues, muscles, bone marrow, blood proteins, enzymes, ferritin, hemosiderin, and transport in plasma. The mechanical properties of iron and its alloys can be evaluated using a variety of tests, including the Brinell test, Rockwell test, the data on iron is so consistent that it is often used to calibrate measurements or to compare tests. An increase in the content will cause a significant increase in the hardness. Maximum hardness of 65 Rc is achieved with a 0. 6% carbon content, because of the softness of iron, it is much easier to work with than its heavier congeners ruthenium and osmium. Because of its significance for planetary cores, the properties of iron at high pressures and temperatures have also been studied extensively
Media related to Mokume-gane at Wikimedia Commons