Lustre or luster is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the latin lux, meaning light, a range of terms are used to describe lustre, such as earthy, metallic and silky. Similarly, the term refers to a glassy lustre. A list of terms is given below. Lustre varies over a continuum, and so there are no rigid boundaries between the different types of lustre. The terms are frequently combined to describe types of lustre. Some minerals exhibit unusual optical phenomena, such as asterism or chatoyancy, a list of such phenomena is given below. Adamantine minerals possess a superlative lustre, which is most notably seen in diamond, such minerals are transparent or translucent, and have a high refractive index. Minerals with an adamantine lustre are uncommon, with examples being cerussite. Minerals with a degree of lustre are referred to as subadamantine, with some examples being garnet. Dull minerals exhibit little to no lustre, due to coarse granulations which scatter light in all directions, a distinction is sometimes drawn between dull minerals and earthy minerals, with the latter being coarser, and having even less lustre.
Greasy minerals resemble fat or grease, a greasy lustre often occurs in minerals containing a great abundance of microscopic inclusions, with examples including opal and cordierite. Many minerals with a greasy lustre feel greasy to the touch, metallic minerals have the lustre of polished metal, and with ideal surfaces will work as a reflective surface. Examples include galena and magnetite, pearly minerals consist of thin transparent co-planar sheets. Light reflecting from these layers give them a lustre reminiscent of pearls, such minerals possess perfect cleavage, with examples including muscovite and stilbite. Resinous minerals have the appearance of resin, chewing gum or plastic, a principal example is amber, which is a form of fossilized resin. Silky minerals have an arrangement of extremely fine fibres, giving them a lustre reminiscent of silk. Examples include asbestos and the satin spar variety of gypsum, a fibrous lustre is similar, but has a coarser texture
Jewellery or jewelry consists of small decorative items worn for personal adornment, such as brooches, necklaces and bracelets. Jewellery may be attached to the body or the clothes, for many centuries metal, often combined with gemstones, has been the normal material for jewellery, but other materials such as shells and other plant materials may be used. It is one of the oldest type of archaeological artefact – with 100, the most widespread influence on jewellery in terms of design and style have come from Asia. Jewellery may be made from a range of materials. Gemstones and similar such as amber and coral, precious metals and shells have been widely used. In most cultures jewellery can be understood as a symbol, for its material properties, its patterns. Jewellery has been made to nearly every body part, from hairpins to toe rings. The word jewellery itself is derived from the jewel, which was anglicised from the Old French jouel. In British English, Indian English, New Zealand English, Hiberno-English, Australian English, both are used in Canadian English, though jewelry prevails by a two to one margin.
Numerous cultures store wedding dowries in the form of jewellery or make jewellery as a means to store or display coins, jewellery has been used as a currency or trade good, an example being the use of slave beads. Many items of jewellery, such as brooches and buckles, originated as functional items. Jewellery can symbolise group membership or status, wearing of amulets and devotional medals to provide protection or ward off evil is common in some cultures. These may take the form of symbols, plants, body parts, in creating jewellery, coins, or other precious items are often used, and they are typically set into precious metals. Alloys of nearly every metal known have been encountered in jewellery, for example, was common in Roman times. Modern fine jewellery usually includes gold, white gold, palladium, most contemporary gold jewellery is made of an alloy of gold, the purity of which is stated in karats, indicated by a number followed by the letter K. American gold jewellery must be of at least 10K purity, many whimsical fashions were introduced in the extravagant eighteenth century.
Cameos that were used in connection with jewellery were the attractive trinkets along with many of the objects such as brooches, ear-rings. Some of the necklets were made of pieces joined with the gold chains were in and bracelets were made sometimes to match the necklet
A Moon landing is the arrival of a spacecraft on the surface of the Moon. This includes both manned and unmanned missions, the first human-made object to reach the surface of the Moon was the Soviet Unions Luna 2 mission, on 13 September 1959. The United States Apollo 11 was the first manned mission to land on the Moon, on 20 July 1969, there have been six manned U. S. landings and numerous unmanned landings, with no soft landings happening from 22 August 1976 until 14 December 2013. To date, the United States is the country to have successfully conducted manned missions to the Moon. Since then, twelve Soviet and U. S. spacecraft have used braking rockets to make landings and perform scientific operations on the lunar surface. In 1966 the USSR accomplished the first soft landings and took the first pictures from the surface during the Luna 9. The U. S. followed with five unmanned Surveyor soft landings, the Soviet Union achieved the first unmanned lunar soil sample return with the Luna 16 probe on 24 September 1970.
This was followed by Luna 20 and Luna 24 in 1972 and 1976, following the failure at launch in 1969 of the first Lunokhod, Luna E-8 No.201, the Luna 17 and Luna 21 were successful unmanned lunar rover missions in 1970 and 1973. Many missions were failures at launch, in addition, several unmanned landing missions achieved the Lunar surface but were unsuccessful, Luna 15, Luna 18, and Luna 23 all crashed on landing, and the U. S. Surveyor 4 lost all radio contact only moments before its landing, more recently, other nations have crashed spacecraft on the surface of the Moon at speeds of around 8,000 kilometres per hour, often at precise, planned locations. These have generally been end-of-life lunar orbiters that, because of system degradations, japans lunar orbiter Hiten impacted the Moons surface on 10 April 1993. The European Space Agency performed a controlled impact with their orbiter SMART-1 on 3 September 2006. Indian Space Research Organisation performed a controlled impact with its Moon Impact Probe on 14 November 2008.
The MIP was a probe from the Indian Chandrayaan-1 lunar orbiter. The Chinese lunar orbiter Change 1 executed a crash onto the surface of the Moon on 1 March 2009. The rover mission Change 3 was launched on 1 December 2013, a total of twelve men have landed on the Moon. Cernan was the last to step off the lunar surface, all Apollo lunar missions had a third crew member who remained on board the Command Module. The last three missions had a rover for increased mobility, in order to go to the Moon, a spacecraft must first leave the gravity well of the Earth
Armenia, officially the Republic of Armenia, is a sovereign state in the South Caucasus region of Eurasia. The Republic of Armenia constitutes only one-tenth of historical Armenia, Armenia is a unitary, multi-party, democratic nation-state with an ancient cultural heritage. Urartu was established in 860 BC and by the 6th century BC it was replaced by the Satrapy of Armenia, in the 1st century BC the Kingdom of Armenia reached its height under Tigranes the Great. Armenia became the first state in the world to adopt Christianity as its official religion, in between the late 3rd century to early years of the 4th century, the state became the first Christian nation. The official date of adoption of Christianity is 301 AD. The ancient Armenian kingdom was split between the Byzantine and Sasanian Empires around the early 5th century, under the Bagratuni dynasty, the Bagratid Kingdom of Armenia was restored in the 9th century. Declining due to the wars against the Byzantines, the fell in 1045. An Armenian principality and a kingdom Cilician Armenia was located on the coast of the Mediterranean Sea between the 11th and 14th centuries.
By the 19th century, Eastern Armenia had been conquered by the Russian Empire, during World War I, Armenians living in their ancestral lands in the Ottoman Empire were systematically exterminated in the Armenian Genocide. By 1920, the state was incorporated into the Transcaucasian Socialist Federative Soviet Republic, in 1936, the Transcaucasian state was dissolved, transforming its constituent states, including the Armenian Soviet Socialist Republic, into full Union republics. The modern Republic of Armenia became independent in 1991 during the dissolution of the Soviet Union, the Republic of Armenia recognises the Armenian Apostolic Church, the worlds oldest national church, as the countrys primary religious establishment. The unique Armenian alphabet was invented by Mesrop Mashtots in 405 AD, Armenia is a member of the Eurasian Economic Union, the Council of Europe and the Collective Security Treaty Organization. Armenia supports the de facto independent Nagorno-Karabakh Republic, which was proclaimed in 1991, the native Armenian name for the country is Հայք.
The name in the Middle Ages was extended to Հայաստան, by addition of the Persian suffix -stan, the further origin of the name is uncertain. It is postulated that the name Hay comes from one of the two confederated, Hittite vassal states—the Ḫayaša-Azzi. The exonym Armenia is attested in the Old Persian Behistun Inscription as Armina, the ancient Greek terms Ἀρμενία and Ἀρμένιοι are first mentioned by Hecataeus of Miletus. Xenophon, a Greek general serving in some of the Persian expeditions, describes many aspects of Armenian village life and he relates that the people spoke a language that to his ear sounded like the language of the Persians. According to the histories of both Moses of Chorene and Michael Chamchian, Armenia derives from the name of Aram, a descendant of Hayk
Forty-eight of the fifty states and the federal district are contiguous and located in North America between Canada and Mexico. The state of Alaska is in the northwest corner of North America, bordered by Canada to the east, the state of Hawaii is an archipelago in the mid-Pacific Ocean. The U. S. territories are scattered about the Pacific Ocean, the geography and wildlife of the country are extremely diverse. At 3.8 million square miles and with over 324 million people, the United States is the worlds third- or fourth-largest country by area, third-largest by land area. It is one of the worlds most ethnically diverse and multicultural nations, paleo-Indians migrated from Asia to the North American mainland at least 15,000 years ago. European colonization began in the 16th century, the United States emerged from 13 British colonies along the East Coast. Numerous disputes between Great Britain and the following the Seven Years War led to the American Revolution. On July 4,1776, during the course of the American Revolutionary War, the war ended in 1783 with recognition of the independence of the United States by Great Britain, representing the first successful war of independence against a European power.
The current constitution was adopted in 1788, after the Articles of Confederation, the first ten amendments, collectively named the Bill of Rights, were ratified in 1791 and designed to guarantee many fundamental civil liberties. During the second half of the 19th century, the American Civil War led to the end of slavery in the country. By the end of century, the United States extended into the Pacific Ocean. The Spanish–American War and World War I confirmed the status as a global military power. The end of the Cold War and the dissolution of the Soviet Union in 1991 left the United States as the sole superpower. The U. S. is a member of the United Nations, World Bank, International Monetary Fund, Organization of American States. The United States is a developed country, with the worlds largest economy by nominal GDP. It ranks highly in several measures of performance, including average wage, human development, per capita GDP. While the U. S. economy is considered post-industrial, characterized by the dominance of services and knowledge economy, the United States is a prominent political and cultural force internationally, and a leader in scientific research and technological innovations.
In 1507, the German cartographer Martin Waldseemüller produced a map on which he named the lands of the Western Hemisphere America after the Italian explorer and cartographer Amerigo Vespucci
An anklet, called ankle chain, ankle bracelet or ankle string, is an ornament worn around the ankle. Barefoot anklets and toe rings historically have been worn for centuries by girls and women in India and they have been worn by Egyptian women since predynastic times. In the United States both casual and more formal anklets became fashionable from the 1930s to the twentieth century. While in western popular culture both younger men and women may wear casual leather anklets, they are popular among barefoot women, formal anklets are used by some women as fashion jewellery. Anklets are an important piece of jewellery in Indian marriages worn along with saris, anklets on both ankles are joined by a chain to limit the step. This practice was prevalent in South East Asia, where the effect was to give a feminine short tripping step. Today, a few western women follow this practice, but rarely in public, more rarely still, some people wear permanent ankle chains and even connecting chains. Anklets were worn as an ornament by Egyptian women of all social classes in ancient Egypt from as early as predynastic times.
The name for anklets was not much different from that of bracelets being menefret except by adding a phrase to denote connection to the feet, during the fourth and sixth dynasties, anklets were usually made of beads threaded in several rows held together with spacer-bars. Anklets were worn by dancers like those shown in the tombs of Kagemni, Ti, in the early twentieth century, anklets were commonly worn by Egyptian women of inner cities. They were called kholkhal and were most classically worn by women of Alexandria, anklets are still commonly worn by dancers in public events. Bronze anklets are visible as early as the Bronze Age in temperate Europe, in an area roughly along the Danube, in the Alpine foreland, up the Rhine to the Atlantic, and down the Rhône. These were found among hoards in these areas, along with other items characteristic of this time. A first-century CE epic of Tamil literature called Cilappatikaram dealt with a woman whose husband was killed trying to sell one of her anklets to a dishonest goldsmith.
The anklets are described in detail in the poem. Rajasthani women wear the heaviest type of anklets, which are silver, the women wear these as costume jewelry, but to show their bravery as a tribe against other rival tribes. The fashion for heavy anklets is declining in India now, but is common in rural areas. In the eastern Indian state of Odisha, which is famous for its jewelry, there are varieties of anklets known as Paunji Nupur
Central Eastern Alps
The term Central Alps is very common in the Geography of Austria as one of the seven major landscape regions of the country. Central Eastern Alps is usually used in connection with the Alpine Club classification of the Eastern Alps, the Central Alps form the eastern part of the Alpine divide, its central chain of mountains, as well as those ranges that extend or accompany it to the north and south. The highest mountain in the Austrian Central Alps is Grossglockner at 3,798 metres, the Central Alps have the highest peaks of the Eastern Alps, and are located between the Northern Limestone Alps and the Southern Limestone Alps, from which they differ in geological composition. The valleys of the rivers Inn and Enns mark their northern boundary, in Austria, the Eastern Alps are divided into the Northern Alps, the Greywacke zone, the Central Alps and the Southern Alps. The latter lie in South Carinthia, but mainly in Northeast Italy, the range has the highest summits in the Eastern Alps and is the most glaciated.
In the transition zone between the East und West Alps its peaks clearly dominate the region to the west, on the perimeter, there are less high, often less rugged mountain chains, like the Gurktal Alps and the eastern foothills. The Eastern Alps is separated from the Western Alps by a line from Lake Constance to Lake Como along the Alpine Rhine valley, the Austroalpine nappes are thrusted over the Penninic nappe stack. Massifs of autochthonous, crystalline rock, which moved at all during Alpine folding. The aforementioned granite intruded near the zone of the Periadriatic Seam. The Western Alps do not have this division into the Northern Limestone Alps, Central Alps, the Austroalpine submerges itself at the eastern edge of the Alps under the Tertiary sediments of the Alpine Foreland in the east and the Pannonian Basin. This fracture zone exhibits active volcanism, in terms of rock, the Ortler main crest is part of the Southern Limestone Alps
Art Nouveau is an international style of art and applied art, especially the decorative arts, that was most popular between 1890 and 1910. A reaction to the art of the 19th century, it was inspired by natural forms and structures, particularly the curved lines of plants. English uses the French name Art Nouveau, according to the philosophy of the style, art should be a way of life. For many well-off Europeans, it was possible to live in an art nouveau-inspired house with art nouveau furniture, fabrics, ceramics including tableware, cigarette cases, artists desired to combine the fine arts and applied arts, even for utilitarian objects. By 1910, Art Nouveau was already out of style and it was replaced as the dominant European architectural and decorative style first by Art Deco and by Modernism. Art Nouveau took its name from the Maison de lArt Nouveau, in France, Art Nouveau was sometimes called by the British term Modern Style due to its roots in the Arts and Crafts Movement, Style moderne, or Style 1900.
It was sometimes called Style Jules Verne, Le Style Métro, Art Belle Époque, in Belgium, where the architectural movement began, it was sometimes termed Style nouille or Style coup de fouet. In Britain, it was known as the Modern Style, or, because of the arts and crafts movement led by Charles Rennie Mackintosh in Glasgow, as the Glasgow style. In Italy, because of the popularity in Italy of designs from Londons Liberty & Co department store, in the United States, due to its association with Louis Comfort Tiffany, it was often called the Tiffany style. In Germany and Scandinavia, a style emerged at about the same time, it was called Jugendstil. In Catalonia the related style was known as Modernisme, in Spain as Modernismo, Arte joven, in Russia, it was called Modern, and Jugendstil, and Nieuwe Kunst in the Netherlands. Some names refer specifically to the forms that were popular with the Art Nouveau artists, Stile Floreal in France, Paling Stijl in the Netherlands. The new art movement had its roots in Britain, in the designs of William Morris.
Early prototypes of the include the Red House of Morris. In France, the style combined several different tendencies, in architecture, it was influenced by the architectural theorist and historian Eugène Viollet-le-Duc, a declared enemy of the historical Beaux-Arts architectural style. For each function its material, for each material its form and this book influenced a generation of architects, including Louis Sullivan, Victor Horta, Hector Guimard, and Antoni Gaudí. The French painters Maurice Denis, Pierre Bonnard and Édouard Vuillard played an important part in integrating fine arts painting with decoration, I believe that before everything a painting must decorate, Denis wrote in 1891. The choice of subjects or scenes is nothing and it is by the value of tones, the colored surface and the harmony of lines that I can reach the spirit and wake up the emotions
Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit. It is defined as the bending of light around the corners of an obstacle or aperture into the region of shadow of the obstacle. In classical physics, the phenomenon is described as the interference of waves according to the Huygens–Fresnel principle. These characteristic behaviors are exhibited when a wave encounters an obstacle or a slit that is comparable in size to its wavelength. Similar effects occur when a wave travels through a medium with a varying refractive index. Diffraction occurs with all waves, including sound waves, water waves, since physical objects have wave-like properties, diffraction occurs with matter and can be studied according to the principles of quantum mechanics. Italian scientist Francesco Maria Grimaldi coined the word diffraction and was the first to record observations of the phenomenon in 1660. If the obstructing object provides multiple, closely spaced openings, a pattern of varying intensity can result.
This is due to the addition, or interference, of different parts of a wave that travel to the observer by different paths, the formalism of diffraction can describe the way in which waves of finite extent propagate in free space. For example, the profile of a laser beam, the beam shape of a radar antenna. The effects of diffraction are often seen in everyday life and this principle can be extended to engineer a grating with a structure such that it will produce any diffraction pattern desired, the hologram on a credit card is an example. Diffraction in the atmosphere by small particles can cause a ring to be visible around a bright light source like the sun or the moon. A shadow of an object, using light from a compact source. The speckle pattern which is observed when laser light falls on a rough surface is a diffraction phenomenon. When deli meat appears to be iridescent, that is diffraction off the meat fibers, all these effects are a consequence of the fact that light propagates as a wave.
Diffraction can occur with any kind of wave, ocean waves diffract around jetties and other obstacles. Sound waves can diffract around objects, which is why one can hear someone calling even when hiding behind a tree. Diffraction can be a concern in some applications, it sets a fundamental limit to the resolution of a camera, telescope
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka, is an island country in South Asia near south-east India. Sri Lanka has maritime borders with India to the northwest and the Maldives to the southwest, Sri Lankas documented history spans 3,000 years, with evidence of pre-historic human settlements dating back to at least 125,000 years. Its geographic location and deep harbours made it of strategic importance from the time of the ancient Silk Road through to World War II. Sri Lanka was known from the beginning of British colonial rule until 1972 as Ceylon, Sri Lankas recent history has been marred by a thirty-year civil war which decisively ended when the Sri Lankan military defeated the Liberation Tigers of Tamil Eelam in 2009. A diverse and multicultural country, Sri Lanka is home to many religions, ethnic groups, in addition to the majority Sinhalese, it is home to large groups of Sri Lankan and Indian Tamils, Burghers, Malays and the aboriginal Vedda. Sri Lanka has a rich Buddhist heritage, and the first known Buddhist writings of Sri Lanka, Sri Lanka is a republic and a unitary state governed by a semi-presidential system.
The legislative capital, Sri Jayawardenepura Kotte, is a suburb of the capital and largest city. Along with the Maldives, Sri Lanka is one of the two countries in South Asia that are rated among high human development on the Human Development Index. In antiquity, Sri Lanka was known to travellers by a variety of names, according to the Mahavamsa, the legendary Prince Vijaya named the land Tambapanni, because his followers hands were reddened by the red soil of the area. In Hindu mythology, such as the Mahabharata, the island was referred to as Lankā, in Tamil, the island is referred to as Eelam. Ancient Greek geographers called it Taprobanā or Taprobanē from the word Tambapanni, as a British crown colony, the island was known as Ceylon, it achieved independence as the Dominion of Ceylon in 1948. The country is known in Sinhalese as Śrī Laṃkā and in Tamil as Ilaṅkai, in 1972, its formal name was changed to Free and Independent Republic of Sri Lanka. Later in 1978 it was changed to the Democratic Socialist Republic of Sri Lanka, as the name Ceylon still appears in the names of a number of organisations, the Sri Lankan government announced in 2011 a plan to rename all those over which it has authority.
The pre-history of Sri Lanka goes back 125,000 years, the era spans the Palaeolithic and early Iron Ages. Among the Paleolithic human settlements discovered in Sri Lanka, Pahiyangala and it is said that Kubera was overthrown by his demon stepbrother Ravana, the powerful emperor who built a mythical flying machine named Dandu Monara. The modern city of Wariyapola is described as Ravanas airport, early inhabitants of Sri Lanka were probably ancestors of the Vedda people, an indigenous people numbering approximately 2,500 living in modern-day Sri Lanka. According to the Mahāvamsa, a written in Pāḷi, the original inhabitants of Sri Lanka are the Yakshas and Nagas. Ancient cemeteries that were used before 600BC and other signs of advanced civilization has discovered in Sri Lanka
In art, the crown may be shown being offered to those on Earth by angels. In religious art, a crown of stars is used similarly to a halo, crowns worn by rulers often contain jewels. A crown is often an emblem of the monarchy, a monarchs government, the word itself is used, particularly in Commonwealth countries, as an abstract name for the monarchy itself, as distinct from the individual who inhabits it. A specific type of crown is employed in heraldry under strict rules, costume headgear imitating a monarchs crown is called a crown. Such costume crowns may be worn by actors portraying a monarch, people at parties, or ritual monarchs such as the king of a Carnival krewe. The nuptial crown, sometimes called a coronal, worn by a bride, in the present day, it is most common in Eastern Orthodox cultures. The Eastern Orthodox marriage service has a section called the crowning, wherein the bride and groom are crowned as king, in Greek weddings, the crowns are diadems usually made of white flowers, synthetic or real, often adorned with silver or mother of pearl.
They are placed on the heads of the newlyweds and are held together by a ribbon of white silk and they are kept by the couple as a reminder of their special day. In Slavic weddings, the crowns are made of ornate metal, designed to resemble an imperial crown. A parish usually owns one set to use for all the couples that are married there since these are more expensive than Greek-style crowns. This was common in Catholic countries in the past, a Crown of thorns according to the Bible, was placed on the head of Jesus before his crucifixion and has become a common symbol of martyrdom. According to Roman Catholic tradition, the Blessed Virgin Mary was crowned as Queen of Heaven after her assumption into heaven and she is often depicted wearing a crown, and statues of her in churches and shrines are ceremonially crowned during May. The Crown of Immortality is common in historical symbolism, dancers of certain traditional Thai dances often wear crowns on their head. These are inspired in the worn by deities and by kings.
Three distinct categories of crowns exist in those monarchies that use crowns or state regalia, worn by monarchs when being crowned. State, worn by monarchs on other state occasions, consort crowns, worn by queens consort, signifying rank granted as a constitutional courtesy protocol. In Classical antiquity, the crown that was awarded to people other than rulers, such as triumphal military generals or athletes, was actually a wreath or chaplet. Numerous crowns of various forms were used in antiquity, such as the Hedjet, the Pschent double crown and it was referred to as the chaplet studded with sunbeams” by Lucian, about 180 AD