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Columbite
Columbite, also called niobite, niobite-tantalite and columbate, with a general chemical formula of , is a black mineral group that is an ore of niobium. It has a submetallic luster, a high density, and is a niobate of iron and manganese. Niobite has many applications in aerospace, construction and the medical industry. Dating columbite minerals is primarily completed by uranium lead (U-Pb) dating, a slow process. Columbite has the same composition and crystal symmetry (orthorhombic) as tantalite. In fact, the two are often grouped together as a semi-singular mineral series called columbite-tantalite or coltan in many mineral guides. However, tantalite has a much greater specific gravity than columbite, more than 8.0 compared to columbite's 5.2. The formation of columbite depends on the concentrations of metals present that affect the crystalline structure of the mineral and the environmental impact. Columbite is a polymorph of tapiolite; they have the same chemical composit ... [...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. Minerals with complex anion groups such as the Silicate mineral, silicates, Sulfate mineral, sulfates, carbonate mineral, carbonates and Phosphate mineral, phosphates are classed separately. Simple oxides *XO form **Periclase group ***Periclase ***Manganosite **Zincite group ***Zincite ***Bromellite ***Tenorite ***Litharge * form **Cuprite **Ice * form **Hematite group ***Corundum ***Hematite ***Ilmenite * form **Rutile group ***Rutile ***Pyrolusite ***Cassiterite **Baddeleyite **Uraninite **Thorianite * form **Spinel group ***Spinel ***Gahnite ***Magnetite ***Franklinite ***Chromite **Chrysoberyl **Columbite *Hydroxide subgroup: **Brucite **Manganite **Romanèchite **Goethite group: ***Diaspore ***Goethite Nickel–Strunz class 4: oxides Internationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niobium
Niobium is a chemical element; it has chemical symbol, symbol Nb (formerly columbium, Cb) and atomic number 41. It is a light grey, crystalline, and Ductility, ductile transition metal. Pure niobium has a Mohs scale of mineral hardness, Mohs hardness rating similar to pure titanium, and it has similar ductility to iron. Niobium oxidizes in Earth's atmosphere very slowly, hence its application in jewelry as a hypoallergenic alternative to nickel. Niobium is often found in the minerals pyrochlore and columbite. Its name comes from Greek mythology: Niobe, daughter of Tantalus, the namesake of tantalum. The name reflects the great similarity between the two elements in their physical and chemical properties, which makes them difficult to distinguish. English chemist Charles Hatchett reported a new element similar to tantalum in 1801 and named it columbium. In 1809, English chemist William Hyde Wollaston wrongly concluded that tantalum and columbium were identical. German chemist He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coltan
Coltan (short for columbite–tantalites and known industrially as tantalite) is a dull black metallic ore from which the elements niobium and tantalum are extracted. The niobium-dominant mineral in coltan is columbite (after niobium's original American name ''columbium''), and the tantalum-dominant mineral is tantalite. Tantalum from coltan is used to manufacture tantalum capacitors which are used for mobile phones, personal computers, automotive electronics, and cameras. Mining in the Democratic Republic of the Congo#Mining resumes (2001–present), Coltan mining is widespread in the Democratic Republic of the Congo. Production and supply Approximately 71% of the global tantalum supply in 2008 was newly mined, 20% was from recycling, and the remainder was from tin slag and inventory. Tantalum minerals are mined in the Democratic Republic of the Congo, Colombia, Rwanda, Australia, Brazil, China, Ethiopia, Mozambique and Kenya. Tantalum is also produced in Thailand and Malaysi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Hatchett
Charles Hatchett Fellow of the Royal Society, FRS FRSE (2 January 1765 – 10 March 1847) was an English mineralogist and analytical chemist who discovered the element niobium, for which he proposed the name "columbium". Hatchett was elected a Fellow of the Linnaean Society in 1795, and of the Royal Society in 1797. Hatchett was elected to the The Club (dining club), Literary Club in London in 1809 and became its treasurer in 1829. Life Charles Hatchett was born in Long Acre, London to John Hatchett (1729–1806), and Elizabeth Hatchett. John Hatchett was "(one of) the coachbuilders of London of the greatest celebrity". He later became a magistrate in Hammersmith. Charles Hatchett attended a private school, Fountayne's, in Marylebone Park, and was a self-taught mineralogist and analytical chemist. On 24 March 1786, Charles Hatchett married Elizabeth Martha Collick (1756–1837) at St Martin-in-the-Fields. Their children included: #John Charles Hatchett (bapt 27 January 1788 St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Winthrop The Younger
John Winthrop the Younger FRS (February 12, 1606 – April 6, 1676) was an English politician and alchemist. An early governor of the Connecticut Colony, he played a large role in the unification of the colony's settlements into a singular colony and obtaining a royal charter for the colony. Early life and career Winthrop was born in Groton, Suffolk, England on February 12, 1606, the son of John Winthrop, founding governor of the Massachusetts Bay Colony, by first wife Mary Forth. He was educated at the Bury St. Edmunds grammar school, King Edward VI School, and Trinity College, Dublin, and he studied law for a short time after 1624 at the Inner Temple, London. After finishing his legal studies in 1627, Winthrop accompanied the ill-fated expedition of the Duke of Buckingham for the relief of the Protestants of La Rochelle in France, and then traveled to Italy, the Ottoman Empire, and the Netherlands, returning to England in 1629. In 1631, he followed his father to Mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tungsten
Tungsten (also called wolfram) is a chemical element; it has symbol W and atomic number 74. It is a metal found naturally on Earth almost exclusively in compounds with other elements. It was identified as a distinct element in 1781 and first isolated as a metal in 1783. Its important ores include scheelite and wolframite, the latter lending the element its alternative name. The free element is remarkable for its robustness, especially the fact that it has the highest melting point of all known elements, melting at . It also has the highest boiling point, at . Its density is 19.254 g/cm3, comparable with that of uranium and gold, and much higher (about 1.7 times) than that of lead. Polycrystalline tungsten is an intrinsically brittle and hard material (under standard conditions, when uncombined), making it difficult to work into metal. However, pure single-crystalline tungsten is more ductile and can be cut with a hard-steel hacksaw. Tungsten occurs in many alloys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ferrotantalite
The mineral group tantalite manganese.html" ;"title="iron.html" ;"title="iron">Fe, manganese">Mn)Tantalum">Ta2oxygen">O6is the primary source of the chemical element tantalum, a corrosion (heat and acid) resistant metal. It is chemically similar to ''columbite'', and the two are often grouped together as a semi-singular mineral called coltan or "columbite-tantalite" in many mineral guides. However, tantalite has a much greater specific gravity than columbite (8.0+ compared to columbite's 5.2). Iron-rich tantalite is the mineral tantalite-(Fe) or ''ferrotantalite'' and manganese-rich is tantalite-(Mn) or ''manganotantalite''. Tantalite is also very close to ''tapiolite''. Those minerals have the same chemical composition, but different crystal symmetry: orthorhombic for tantalite and tetragonal for tapiolite. Tantalite is black to brown in both color and streak. Manganese-rich tantalites can be brown and translucent. Occurrence Tantalite occurs in granitic pegmatites that are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tantalum
Tantalum is a chemical element; it has Symbol (chemistry), symbol Ta and atomic number 73. It is named after Tantalus, a figure in Greek mythology. Tantalum is a very hard, ductility, ductile, lustre (mineralogy), lustrous, blue-gray transition metal that is highly corrosion-resistant. It is part of the refractory metals group, which are widely used as components of strong superalloy, high-melting-point alloys. It is a group 5 element, along with vanadium and niobium, and it always occurs in geologic sources together with the chemically similar niobium, mainly in the mineral groups tantalite, columbite, and coltan. The chemical inertness and very high melting point of tantalum make it valuable for laboratory and industrial equipment such as Chemical reactor, reaction vessels and vacuum furnaces. It is used in tantalum capacitors for electronic equipment such as computers. It is being investigated for use as a material for high-quality superconducting resonators in quantum proces ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christopher Columbus
Christopher Columbus (; between 25 August and 31 October 1451 – 20 May 1506) was an Italians, Italian explorer and navigator from the Republic of Genoa who completed Voyages of Christopher Columbus, four Spanish-based voyages across the Atlantic Ocean sponsored by the Catholic Monarchs, opening the way for the widespread European Age of Discovery, exploration and colonization of the Americas. His expeditions were the first known European contact with the Caribbean and Central and South America. The name ''Christopher Columbus'' is the Anglicisation (linguistics), anglicization of the Latin . Growing up on the coast of Liguria, he went to sea at a young age and traveled widely, as far north as the British Isles and as far south as what is now Ghana. He married Portuguese noblewoman Filipa Moniz Perestrelo, who bore a son, Diego Columbus, Diego, and was based in Lisbon for several years. He later took a Castilian mistress, Beatriz Enríquez de Arana, who bore a son, Ferdinand ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
