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Magnesium Aluminate Spinel
Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , which means ''spine'' in reference to its pointed crystals. Properties Spinel crystallizes in the isometric system; common crystal forms are octahedra, usually twinned. It has no true cleavage, but shows an octahedral parting and a conchoidal fracture. Its hardness is 8, its specific gravity is 3.5–4.1, and it is transparent to opaque with a vitreous to dull luster. It may be colorless, but is usually various shades of red, lavender, blue, green, brown, black, or yellow. Some spinels are among the most famous gemstones; among them are the Black Prince's Ruby and the "Timur ruby" in the British Crown Jewels, and the "Côte de Bretagne", formerly from the French Crown jewels. The Samarian Spinel is the largest known spinel in the world, weighing . The transparent red spinels were called spinel-rubies or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxide Minerals
The oxide mineral class includes those minerals in which the oxide anion (O2−) is bonded to one or more metal alloys. The hydroxide-bearing minerals are typically included in the oxide class. The minerals with complex anion groups such as the silicates, sulfates, carbonates and phosphates are classed separately. Simple oxides: *XO **Periclase group ***Periclase ***Manganosite **Zincite group ***Zincite *** Bromellite ***Tenorite ***Litharge * **Cuprite **Ice * **Hematite group ***Corundum ***Hematite ***Ilmenite * **Rutile group ***Rutile ***Pyrolusite *** Cassiterite ** Baddeleyite **Uraninite **Thorianite * **Spinel group ***Spinel ***Gahnite ***Magnetite ***Franklinite *** Chromite **Chrysoberyl **Columbite *Hydroxide subgroup: **Brucite **Manganite ** Romanèchite **Goethite group: ***Diaspore ***Goethite Nickel–Strunz Classification -04- Oxides IMA-CNMNC proposes a new hierarchical scheme (Mills et al., 2009). This list uses it to mod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Gravity
Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water (molecule), water at its densest (at ); for gases, the reference is air at room temperature (). The term "relative density" (often abbreviated r.d. or RD) is often preferred in scientific usage, whereas the term "specific gravity" is deprecation, deprecated. If a substance's relative density is less than 1 then it is less dense than the reference; if greater than 1 then it is denser than the reference. If the relative density is exactly 1 then the densities are equal; that is, equal volumes of the two substances have the same mass. If the reference material is water, then a substance with a relative density (or specific gravity) less than 1 will float in water. For example, an ice cube, with a relative density of about 0.91, will float. A substance wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tajikistan
Tajikistan (, ; tg, Тоҷикистон, Tojikiston; russian: Таджикистан, Tadzhikistan), officially the Republic of Tajikistan ( tg, Ҷумҳурии Тоҷикистон, Jumhurii Tojikiston), is a landlocked country in Central Asia. It has an area of and an estimated population of 9,749,625 people. Its capital and largest city is Dushanbe. It is bordered by Afghanistan to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east. It is separated narrowly from Pakistan by Afghanistan's Wakhan Corridor. The traditional homelands of the Tajiks include present-day Tajikistan as well as parts of Afghanistan and Uzbekistan. The territory that now constitutes Tajikistan was previously home to several ancient cultures, including the city of Sarazm of the Neolithic and the Bronze Age and was later home to kingdoms ruled by people of different faiths and cultures, including the Oxus civilization, Andronovo culture, Buddhism, Nestorian Ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gorno Badakhshan
Gorno-Badakhshan, officially the Badakhshan Mountainous Autonomous Region,, abbr. / is an autonomous region in eastern Tajikistan, in the Pamir Mountains. It makes up nearly forty-five percent of the country's land area, but only two percent of its population.''Population of the Republic of Tajikistan as of 1 January 2008'', State Statistical Committee, Dushanbe, 2008 Name The official English name of the autonomous region is the Badakhshan Mountainous Autonomous Region. The name "Badakhshan" (russian: Бадахшан, Badakhshan; tg, Бадахшон, Badaxşon) is derived from the Sasanian title or . "Gorno-Badakhshan" literally means "mountainous Badakhshan" and is derived from the Russian name of the autonomous region, . The Russian abbreviation "GBAO" is also commonly used in English-language publications by national and international bodies such as the government of Tajikistan and the United Nations. History Prior to 1895, several semi-self governing statelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanskrit
Sanskrit (; attributively , ; nominally , , ) is a classical language belonging to the Indo-Aryan branch of the Indo-European languages. It arose in South Asia after its predecessor languages had diffused there from the northwest in the late Bronze Age. Sanskrit is the sacred language of Hinduism, the language of classical Hindu philosophy, and of historical texts of Buddhism and Jainism. It was a link language in ancient and medieval South Asia, and upon transmission of Hindu and Buddhist culture to Southeast Asia, East Asia and Central Asia in the early medieval era, it became a language of religion and high culture, and of the political elites in some of these regions. As a result, Sanskrit had a lasting impact on the languages of South Asia, Southeast Asia and East Asia, especially in their formal and learned vocabularies. Sanskrit generally connotes several Old Indo-Aryan language varieties. The most archaic of these is the Vedic Sanskrit found in the Rig Veda, a colle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxus River
The Amu Darya, tk, Amyderýa/ uz, Amudaryo// tg, Амударё, Amudaryo ps, , tr, Ceyhun / Amu Derya grc, Ὦξος, Ôxos (also called the Amu, Amo River and historically known by its Latin name or Greek ) is a major river in Central Asia and Afghanistan. Rising in the Pamir Mountains, north of the Hindu Kush, the Amu Darya is formed by the confluence of the Vakhsh and Panj rivers, in the Tigrovaya Balka Nature Reserve on the border between Afghanistan and Tajikistan, and flows from there north-westwards into the southern remnants of the Aral Sea. In its upper course, the river forms part of Afghanistan's northern border with Tajikistan, Uzbekistan, and Turkmenistan. In ancient history, the river was regarded as the boundary of Greater Iran with "Turan", which roughly corresponded to present-day Central Asia.B. SpulerĀmū Daryā in Encyclopædia Iranica, online ed., 2009 The Amu Darya has a flow of about 70 cubic kilometres per year on average. Names In classical anti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Panj River
The Panj (russian: Пяндж; fa, رودخانه پنج) (; tg, Панҷ, پنج), traditionally known as the Ochus River and also known as ''Pyandzh'' (derived from its Russian name "Пяндж"), is a tributary of the Amu Darya. The river is long and has a basin area of .Пяндж (река) It forms a considerable part of the – border. The river is formed by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asia
Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an area of , about 30% of Earth's total land area and 8.7% of Earth's total surface area. The continent, which has long been home to the majority of the human population, was the site of many of the first civilizations. Its 4.7 billion people constitute roughly 60% of the world's population. In general terms, Asia is bounded on the east by the Pacific Ocean, on the south by the Indian Ocean, and on the north by the Arctic Ocean. The border of Asia with Europe is a historical and cultural construct, as there is no clear physical and geographical separation between them. It is somewhat arbitrary and has moved since its first conception in classical antiquity. The division of Eurasia into two continents reflects East–West cultural, linguistic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Badakhshan
Badakhshan is a historical region comprising parts of modern-day north-eastern Afghanistan, eastern Tajikistan, and Taxkorgan Tajik Autonomous County in China. Badakhshan Province is one of the 34 provinces of Afghanistan. Much of historic Badakhshan lies within Tajikistan's Gorno-Badakhshan Autonomous Region, in the southeastern part of the country. The music of Badakhshan is an important part of the region's cultural heritage. Name The name "Badakhshan" ( fa, بدخشان, ''Badaxšân''; ps, بدخشان; tg, Бадахшон, ''Badaxşon''; ) is derived from the Sasanian official title ''bēdaxš'' or ''badaxš'', which may be from an earlier *pati-axša; the suffix -''ān'' indicates that the country belonged, or had been assigned as a fief, to a person holding the rank of a '' badaxš''. People Badakhshan has a diverse ethnolinguistic and religious community. Tajiks and Pamiris are the majority while a tiny minority of Kyrgyzs and Uzbeks also are found in their ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corundum
Corundum is a crystalline form of aluminium oxide () typically containing traces of iron, titanium, vanadium and chromium. It is a rock-forming mineral. It is a naturally transparent material, but can have different colors depending on the presence of transition metal impurities in its crystalline structure. Corundum has two primary gem varieties: ruby and sapphire. Rubies are red due to the presence of chromium, and sapphires exhibit a range of colors depending on what transition metal is present. A rare type of sapphire, padparadscha sapphire, is pink-orange. The name "corundum" is derived from the Tamil- Dravidian word ''kurundam'' (ruby-sapphire) (appearing in Sanskrit as ''kuruvinda''). Because of corundum's hardness (pure corundum is defined to have 9.0 on the Mohs scale), it can scratch almost all other minerals. It is commonly used as an abrasive on sandpaper and on large tools used in machining metals, plastics, and wood. Emery, a variety of corundum with no value a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Jewels Of The United Kingdom
The Crown Jewels of the United Kingdom, originally the Crown Jewels of England, are a collection of royal ceremonial objects kept in the Tower of London which include the Coronation of the British monarch, coronation regalia and vestments worn by British monarchs. Symbols of over 800 years of monarchy, the coronation regalia are the only working set in Europe and the collection is the most historically complete of any regalia in the world. Objects used to invest and crown British monarchs variously denote their role as head of state of the United Kingdom and other countries of the Commonwealth of Nations, Commonwealth, Supreme Governor of the Church of England, and head of the British armed forces. They feature heraldic devices and national emblems of England, Scotland, Wales and Northern Ireland. Use of regalia by monarchs in England can be traced back to when it was converted to Christianity in the Early Middle Ages. A permanent set of coronation regalia, once belonging to E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
