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Turquoise
Turquoise is an opaque, blue-to-green mineral that is a hydrated phosphate of copper and aluminium, with the chemical formula . It is rare and valuable in finer grades and has been prized as a gemstone and ornamental stone for thousands of years owing to its unique hue. Like most other opaque gems, turquoise has been devalued by the introduction of treatments, imitations and synthetics into the market. The robin's egg blue or sky blue color of the Persian turquoise mined near the modern city of Nishapur in Iran has been used as a guiding reference for evaluating turquoise quality. Names The word ''turquoise'' dates to the 17th century and is derived from the French ''turquois'' meaning "Turkish" because the mineral was first brought to Europe through the Ottoman Empire.Turquoise . minerals.usgs.gov Howe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turquoise (color)
Turquoise ( ) is a blue-green color, based on the mineral of the same name. The word ''turquoise'' dates to the 17th century and is derived from the French , meaning 'Turkish', because the mineral was first brought to Europe through Turkey from mines in the historical Khorasan province of Iran (Persia) and Afghanistan. The first recorded use of ''turquoise'' as a color name in English was in 1573. The X11 color named turquoise is displayed on the right. Turquoise gemstones Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula Cu Al6( P O4)4(O H)8·4 H2O. It is rare and valuable in finer grades and has been prized as a gem and ornamental stone for thousands of years owing to its unique hue. In many cultures of the Old and New Worlds, this gemstone has been esteemed for thousands of years as a holy stone, a bringer of good fortune or a talisman. The oldest evidence for this claim was found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nishapur
Nishapur or officially Romanized as Neyshabur ( fa, ;Or also "نیشاپور" which is closer to its original and historic meaning though it is less commonly used by modern native Persian speakers. In Persian poetry, the name of this city is written and pronounced as "نِشابور" (without the usage of "پ" or "ب"). In modern times and among the general public and the Persian mass media, "نیشابور" is the most commonly used style of pronunciation and spelling of this city though "نیشاپور" is also correct. Nišâpur, Nişapur, Nīshābūr, or Neyshapur are also the other Romanizations of this city. from Middle Persian ''"New-Shapuhr"'', meaning: "The New City of Shapur", "The Fair Shapur", or "The Perfect built of Shapur") is the second-largest city of Razavi Khorasan Province in the Northeast of Iran. Nishapur is situated in a fertile plain at the foot of Binalud Mountain Range and has been the historic capital of the Western Quarter of Greater Khorasan, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass
Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling ( quenching) of the molten form; some glasses such as volcanic glass are naturally occurring. The most familiar, and historically the oldest, types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz), the primary constituent of sand. Soda–lime glass, containing around 70% silica, accounts for around 90% of manufactured glass. The term ''glass'', in popular usage, is often used to refer only to this type of material, although silica-free glasses often have desirable properties for applications in modern communications technology. Some objects, such as drinking glasses and eyeglasses, are so commonly made of silicate-based glass that they are simply called by the name of the material. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aztec
The Aztecs () were a Mesoamerican culture that flourished in central Mexico in the post-classic period from 1300 to 1521. The Aztec people included different ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica from the 14th to the 16th centuries. Aztec culture was organized into city-states ('' altepetl''), some of which joined to form alliances, political confederations, or empires. The Aztec Empire was a confederation of three city-states established in 1427: Tenochtitlan, city-state of the Mexica or Tenochca; Texcoco; and Tlacopan, previously part of the Tepanec empire, whose dominant power was Azcapotzalco. Although the term Aztecs is often narrowly restricted to the Mexica of Tenochtitlan, it is also broadly used to refer to Nahua polities or peoples of central Mexico in the prehispanic era, as well as the Spanish colonial era (1521–1821). The definitions of Aztec and Aztecs ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmenistan to the north, by Afghanistan and Pakistan to the east, and by the Gulf of Oman and the Persian Gulf to the south. It covers an area of , making it the 17th-largest country. Iran has a population of 86 million, making it the 17th-most populous country in the world, and the second-largest in the Middle East. Its largest cities, in descending order, are the capital Tehran, Mashhad, Isfahan, Karaj, Shiraz, and Tabriz. The country is home to one of the world's oldest civilizations, beginning with the formation of the Elamite kingdoms in the fourth millennium BC. It was first unified by the Medes, an ancient Iranian people, in the seventh century BC, and reached its territorial height in the sixth century BC, when Cyrus the Great f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sky Blue
Sky blue is a shade of light blue comparable to that of a clear daytime sky. The term (as "sky blew") is attested from 1681. A 1585 translation of Nicolas de Nicolay's 1576 ''Les navigations, peregrinations et voyages faicts en la Turquie'' includes "the tulbant urbanof the merchant must be ''skie coloured''". Displayed at right is the web colour ''sky blue''. Variations Celeste Celeste (, , ) is the colloquial name for the pale turquoise blue colour. The same word, meaning "of the sky", is used in Spanish and Italian for the colour. In English, this colour may also be referred to as Italian sky blue. The Japanese equivalent is known as ''sora iro'' or ''mizuiro'', referring to the colour of the sky or its reflection on the sea. Bleu celeste ("sky blue") is a rarely occurring tincture in heraldry (not being one of the seven main colours or metals or the three "staynard colours"). This tincture is sometimes also called ciel or simply celeste. It is depicted in a li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemstone
A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, and obsidian) and occasionally organic materials that are not minerals (such as amber, jet, and pearl) are also used for jewelry and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity and notoriety are other characteristics that lend value to gemstones. Apart from jewelry, from earliest antiquity engraved gems and hardstone carvings, such as cups, were major luxury art forms. A gem expert is a gemologist, a gem maker is called a lapidarist or gemcutter; a diamond cutter is called a diamantaire. Characteristics and classification The traditional classification in the West ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminium
Aluminium (aluminum in American and Canadian English) is a chemical element with the symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately one third that of steel. It has a great affinity towards oxygen, and forms a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver, both in its color and in its great ability to reflect light. It is soft, non-magnetic and ductile. It has one stable isotope, 27Al; this isotope is very common, making aluminium the twelfth most common element in the Universe. The radioactivity of 26Al is used in radiodating. Chemically, aluminium is a post-transition metal in the boron group; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state. The aluminium cation Al3+ is small and highly charged; as such, it is polarizing, and bonds aluminium forms tend towards covalency. The strong affinity tow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triclinic
180px, Triclinic (a ≠ b ≠ c and α ≠ β ≠ γ ) In crystallography, the triclinic (or anorthic) crystal system is one of the 7 crystal systems. A crystal system is described by three basis vectors. In the triclinic system, the crystal is described by vectors of unequal length, as in the orthorhombic system. In addition, the angles between these vectors must all be different and may not include 90°. The triclinic lattice is the least symmetric of the 14 three-dimensional Bravais lattices. It has (itself) the minimum symmetry all lattices have: points of inversion at each lattice point and at 7 more points for each lattice point: at the midpoints of the edges and the faces, and at the center points. It is the only lattice type that itself has no mirror planes. Crystal classes The triclinic crystal system class names, examples, Schönflies notation, Hermann-Mauguin notation, point groups, International Tables for Crystallography space group number, orbifold, type, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper
Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement. Copper is one of the few metals that can occur in nature in a directly usable metallic form ( native metals). This led to very early human use in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a shape in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mohs Scale Of Mineral Hardness
The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by the German geologist and mineralogist Friedrich Mohs, in his book ''"Versuch einer Elementar-Methode zur naturhistorischen Bestimmung und Erkennung der Fossilien"''; it is one of several definitions of hardness in materials science, some of which are more quantitative. The method of comparing hardness by observing which minerals can scratch others is of great antiquity, having been mentioned by Theophrastus in his treatise ''On Stones'', , followed by Pliny the Elder in his ''Naturalis Historia'', . The Mohs scale is useful for identification of minerals in the field, but is not an accurate predictor of how well materials endure in an industrial setting – ''toughness''. Minerals The Mohs scale of mineral hardness is based on the ability ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptocrystalline
Cryptocrystalline is a rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light. Among the sedimentary rocks, chert and flint are cryptocrystalline. Carbonado, a form of diamond, is also cryptocrystalline. Volcanic rocks, especially of the felsic type such as felsites and rhyolites, may have a cryptocrystalline groundmass as distinguished from pure obsidian (felsic) or tachylyte (mafic), which are natural rock glasses. Agate and onyx are examples of cryptocrystalline silica ( chalcedony). See also * List of rock textures * Macrocrystalline * Microcrystalline * Nanocrystalline A nanocrystalline (NC) material is a polycrystalline material with a crystallite size of only a few nanometers. These materials fill the gap between amorphous materials without any long range order and conventional coarse-grained materials. Defi ... * Rock microstructure References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
