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Tourmaline Cut
Tourmaline ( ) is a crystalline Silicate mineral, silicate mineral group in which boron is compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is a gemstone and can be found in a wide variety of colors. The term is derived from the Sinhala language, Sinhalese "tōramalli", which refers to the carnelian gemstones. History Brightly colored Ceylonese gem tourmalines were brought to Europe in great quantities by the Dutch East India Company to satisfy a demand for curiosities and gems. Tourmaline was sometimes called the "Ceylonese Magnet" because it could attract and then repel hot ashes due to its Pyroelectricity, pyroelectric properties. Tourmalines were used by chemists in the 19th century to polarize light by shining rays onto a cut and polished surface of the gem. Species and varieties Commonly encountered species and varieties: Schorl species: : Brownish black to black—''schorl'', Dravite species: from the Drave dis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclosilicate
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually considered a silicate mineral. Silica is found in nature as the mineral quartz, and its polymorphism (materials science), polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this carbonate–silicate cycle, geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawater. The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinhala Language
Sinhala ( ; , ''siṁhala'', ), sometimes called Sinhalese (), is an Indo-Aryan languages, Indo-Aryan language primarily spoken by the Sinhalese people of Sri Lanka, who make up the largest ethnic group on the island, numbering about 16 million. Sinhala is also spoken as the first language by other ethnic groups in Sri Lanka, totalling about 2 million people as of 2001. It is written using the Sinhala script, which is a Brahmic scripts, Brahmic script closely related to the Grantha script of South India. Sinhala is one of the official and national languages of Sri Lanka. Along with Pali, it played a major role in the development of Theravada, Theravada Buddhist literature. The early form of the Sinhala language, is attested as early as the 3rd century BCE. The language of these inscriptions with long vowels and aspirated consonants is a Prakrit similar to Magadhi, a regional associate of the Middle Indian Prakrits that has been used during the time of the Buddha. The closest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greek Language
Greek ( el, label=Modern Greek, Ελληνικά, Elliniká, ; grc, Ἑλληνική, Hellēnikḗ) is an independent branch of the Indo-European family of languages, native to Greece, Cyprus, southern Italy (Calabria and Salento), southern Albania, and other regions of the Balkans, the Black Sea coast, Asia Minor, and the Eastern Mediterranean. It has the longest documented history of any Indo-European language, spanning at least 3,400 years of written records. Its writing system is the Greek alphabet, which has been used for approximately 2,800 years; previously, Greek was recorded in writing systems such as Linear B and the Cypriot syllabary. The alphabet arose from the Phoenician script and was in turn the basis of the Latin, Cyrillic, Armenian, Coptic, Gothic, and many other writing systems. The Greek language holds a very important place in the history of the Western world. Beginning with the epics of Homer, ancient Greek literature includes many works of lasting impo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emerald
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium.Hurlbut, Cornelius S. Jr. and Kammerling, Robert C. (1991) ''Gemology'', John Wiley & Sons, New York, p. 203, . Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds are highly included, so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate. Etymology The word "emerald" is derived (via fro, esmeraude and enm, emeraude), from Vulgar Latin: ''esmaralda''/''esmaraldus'', a variant of Latin ''smaragdus'', which was a via grc, σμάραγδος (smáragdos; "green gem") from a Semitic language. According to Webster's Dictionary the term emerald was first used in the 14th century. Properties determining value Emeralds, like all colored gemstones, are graded using four basic parameters–the four ''C''s of connoisseurship: ''color'', ''clarity,'' ''cut'' and ''carat weight''. N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indigo
Indigo is a deep color close to the color wheel blue (a primary color in the RGB color space), as well as to some variants of ultramarine, based on the ancient dye of the same name. The word "indigo" comes from the Latin word ''indicum'', meaning "Indian", as the dye was originally exported to Europe from India. It is traditionally regarded as a color in the visible spectrum, as well as one of the seven colors of the rainbow: the color between blue and violet; however, sources differ as to its actual position in the electromagnetic spectrum. The first known recorded use of indigo as a color name in English was in 1289. History ''Indigofera tinctoria'' and related species were cultivated in East Asia, Egypt, India, Bangladesh and Peru in antiquity. The earliest direct evidence for the use of indigo dates to around 4000 BC and comes from Huaca Prieta, in contemporary Peru. Pliny the Elder mentions India as the source of the dye after which it was named. It was importe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubellite (gem)
Rubellite is the red or pink variety of tourmaline and is a member of elbaite. Rubellite is also the rarest gem in its gem family. It is occasionally mistaken for ruby. These gems typically contain inclusions. Notable places where rubellite can be mined includes Afghanistan, Brazil, Madagascar, Myanmar, Nigeria, Russia, and the United States. Name Rubellite is named after the Latin word for red. The word rubellite was first used in the year 1794. The gem is also called Aphrite, Apyrite, Rubelite, or Rubylite. Value Rubellite is the most expensive and prized gem in the tourmaline Tourmaline ( ) is a crystalline silicate mineral group in which boron is compounded with elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. Tourmaline is a gemstone and can be found in a wide variety of colors. The ... group. The most valuable rubellites are those that are colored red and have no brown. Ones that are of ruby color are the most valuable. Refere ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Italy
Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical region. Italy is also considered part of Western Europe, and shares land borders with France, Switzerland, Austria, Slovenia and the enclaved microstates of Vatican City and San Marino. It has a territorial exclave in Switzerland, Campione. Italy covers an area of , with a population of over 60 million. It is the third-most populous member state of the European Union, the sixth-most populous country in Europe, and the tenth-largest country in the continent by land area. Italy's capital and largest city is Rome. Italy was the native place of many civilizations such as the Italic peoples and the Etruscans, while due to its central geographic location in Southern Europe and the Mediterranean, the country has also historically been home ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elba
Elba ( it, isola d'Elba, ; la, Ilva) is a Mediterranean island in Tuscany, Italy, from the coastal town of Piombino on the Italian mainland, and the largest island of the Tuscan Archipelago. It is also part of the Arcipelago Toscano National Park, and the third largest island in Italy, after Sicily and Sardinia. It is located in the Tyrrhenian Sea about east of the French island of Corsica. The island is part of the province of Livorno and is divided into seven municipalities, with a total population of about 30,000 inhabitants which increases considerably during the summer. The municipalities are Portoferraio (which is also the island's principal town), Campo nell'Elba, Capoliveri, Marciana, Marciana Marina, Porto Azzurro, and Rio. Elba was the site of Napoleon's first exile, from 1814 to 1815. Geography Elba is the largest remaining stretch of land from the ancient tract that once connected the Italian peninsula to Corsica. The northern coast faces the Ligurian Sea, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elbaite
Elbaite, a sodium, lithium, aluminium boro-silicate, with the chemical composition Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4, is a mineral species belonging to the six-member ring cyclosilicate tourmaline group. Elbaite forms three series, with dravite, with fluor-liddicoatite, and with schorl. Due to these series, specimens with the ideal endmember formula are not found occurring naturally. As a gemstone, elbaite is a desirable member of the tourmaline group because of the variety and depth of its colours and quality of the crystals. Originally discovered on the island of Elba, Italy in 1913, it has since been found in many parts of the world. In 1994, a major locality was discovered in Canada, at O'Grady Lakes in the Yukon. Elbaite forms in igneous and metamorphic rocks and veins in association with lepidolite, microcline, and spodumene in granite pegmatites; with andalusite and biotite in schist; and with molybdenite and cassiterite in massive hydrothermal replacement deposits. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carinthia (state)
Carinthia (german: Kärnten ; sl, Koroška ) is the southernmost Austrian state, in the Eastern Alps, and is noted for its mountains and lakes. The main language is German. Its regional dialects belong to the Southern Bavarian group. Carinthian Slovene dialects, forms of a South Slavic language that predominated in the southeastern part of the region up to the first half of the 20th century, are now spoken by a small minority in the area. Carinthia's main industries are tourism, electronics, engineering, forestry, and agriculture. Name The etymology of the name "Carinthia", similar to Carnia or Carniola, has not been conclusively established. The ''Ravenna Cosmography'' (about AD 700) referred to a Slavic "Carantani" tribe as the eastern neighbours of the Bavarians. In his ''History of the Lombards'', the 8th-century chronicler Paul the Deacon mentions "Slavs in Carnuntum, which is erroneously called Carantanum" (''Carnuntum, quod corrupte vocitant Carantanum'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroelectricity
Pyroelectricity (from the two Greek words ''pyr'' meaning fire, and electricity) is a property of certain crystals which are naturally electrically polarized and as a result contain large electric fields. Pyroelectricity can be described as the ability of certain materials to generate a temporary voltage when they are heated or cooled. The change in temperature modifies the positions of the atoms slightly within the crystal structure, such that the polarization of the material changes. This polarization change gives rise to a voltage across the crystal. If the temperature stays constant at its new value, the pyroelectric voltage gradually disappears due to leakage current. The leakage can be due to electrons moving through the crystal, ions moving through the air, or current leaking through a voltmeter attached across the crystal. Explanation Pyroelectric charge in minerals develops on the opposite faces of asymmetric crystals. The direction in which the propagation of the char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch East India Company
The United East India Company ( nl, Verenigde Oostindische Compagnie, the VOC) was a chartered company established on the 20th March 1602 by the States General of the Netherlands amalgamating existing companies into the first joint-stock company in the world, granting it a 21-year monopoly to carry out trade activities in Asia. Shares in the company could be bought by any resident of the United Provinces and then subsequently bought and sold in open-air secondary markets (one of which became the Amsterdam Stock Exchange). It is sometimes considered to have been the first multinational corporation. It was a powerful company, possessing quasi-governmental powers, including the ability to wage war, imprison and execute convicts, negotiate treaties, strike its own coins, and establish colonies. They are also known for their international slave trade. Statistically, the VOC eclipsed all of its rivals in the Asia trade. Between 1602 and 1796 the VOC sent almost a million Eur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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