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Manaccanite
Ilmenite is a titanium-iron oxide mineral with the idealized formula . It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing inks, fabrics, plastics, paper, sunscreen, food and cosmetics. Structure and properties Ilmenite is a heavy (specific gravity 4.7), moderately hard (Mohs hardness 5.6 to 6), opaque black mineral with a submetallic luster. It is almost always massive, with thick tabular crystals being quite rare. It shows no discernible cleavage, breaking instead with a conchoidal to uneven fracture. Ilmenite crystallizes in the trigonal system with space group ''R''. The ilmenite crystal structure consists of an ordered derivative of the corundum structure; in corundum all cations are identical but in ilmenite Fe2+ and Ti4+ ions occupy alternating layers perpendicular to the trigonal c axis. Pure ilmenite is paramagnetic (showing only very weak attra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxide Mineral
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 modify ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornwall
Cornwall (; kw, Kernow ) is a historic county and ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people. Cornwall is bordered to the north and west by the Atlantic Ocean, to the south by the English Channel, and to the east by the county of Devon, with the River Tamar forming the border between them. Cornwall forms the westernmost part of the South West Peninsula of the island of Great Britain. The southwesternmost point is Land's End and the southernmost Lizard Point. Cornwall has a population of and an area of . The county has been administered since 2009 by the unitary authority, Cornwall Council. The ceremonial county of Cornwall also includes the Isles of Scilly, which are administered separately. The administrative centre of Cornwall is Truro, its only city. Cornwall was formerly a Brythonic kingdom and subsequently a royal duchy. It is the cultural and ethnic origin of the Cornish dias ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heavy Mineral Sands Ore Deposits
Heavy mineral sands are a class of ore deposit which is an important source of zirconium, titanium, thorium, tungsten, rare-earth elements, the industrial minerals diamond, sapphire, garnet, and occasionally precious metals or gemstones. Heavy mineral sands are placer deposits formed most usually in beach environments by concentration due to the specific gravity of the mineral grains. It is equally likely that some concentrations of heavy minerals (aside from the usual gold placers) exist within streambeds, but most are of a low grade and are relatively small. Grade and tonnage distribution The grade of a typical heavy mineral sand ore deposit is usually low. Within the 21st century, the lowest cut-off grades of heavy minerals, as a total heavy mineral (THM) concentrate from the bulk sand, in most ore deposits of this type is around 1% heavy minerals, although several are higher grade. Of this total heavy mineral concentrate (THM), the components are typically * Zircon, from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leucoxene
Leucoxene is a fine granular alteration product of titanium minerals. It varies in color from yellow to brown. It consists mainly of rutile or anatase. It is observed in some igneous rocks and iron ore deposits as the result of the alteration of ilmenite, perovskite, or titanite Titanite, or sphene (from the Greek ''sphenos'' (σφηνώ), meaning wedge), is a calcium titanium nesosilicate mineral, Ca Ti Si O5. Trace impurities of iron and aluminium are typically present. Also commonly present are rare earth metals .... References * Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., Mindat.org Oxide minerals {{oxide-mineral-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Minerals'; p. 1. In the series ''Geology: Landforms, Minerals, and Rocks''. Rosen Publishing Group. The geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or are organic compounds in the sense of chemistry (such as mellite). Moreover, living organisms often synthesize inorganic minerals (such as hydroxylapatite) that also occur in rocks. The concept of mineral is distinct from rock, which is any bulk solid geologic material that is relatively homogeneous at a large enough scale. A rock may consist of one type of mineral, or may be an aggregate of two or more different types of minerals, spacially segregated into distinct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weathering
Weathering is the deterioration of rocks, soils and minerals as well as wood and artificial materials through contact with water, atmospheric gases, and biological organisms. Weathering occurs ''in situ'' (on site, with little or no movement), and so is distinct from erosion, which involves the transport of rocks and minerals by agents such as water, ice, snow, wind, waves and gravity. Weathering processes are divided into ''physical'' and ''chemical weathering''. Physical weathering involves the breakdown of rocks and soils through the mechanical effects of heat, water, ice, or other agents. Chemical weathering involves the chemical reaction of water, atmospheric gases, and biologically produced chemicals with rocks and soils. Water is the principal agent behind both physical and chemical weathering, though atmospheric oxygen and carbon dioxide and the activities of biological organisms are also important. Chemical weathering by biological action is also known as biological wea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metasomatism
Metasomatism (from the Greek μετά ''metá'' "change" and σῶμα ''sôma'' "body") is the chemical alteration of a rock by hydrothermal and other fluids. It is the replacement of one rock by another of different mineralogical and chemical composition. The minerals which compose the rocks are dissolved and new mineral formations are deposited in their place. Dissolution and deposition occur simultaneously and the rock remains solid. Synonyms to the word metasomatism are metasomatose and metasomatic process. The word metasomatose can also be used as a name for specific varieties of metasomatism (for example '' Mg-metasomatose'' and '' Na-metasomatose''). Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source. In the igneous environment, metasomatism creates skarns, greisen, and may affect hornfels in the contact metamorphic aureole adjacent to an intrusive rock mass. In the metamorphic environment, metasomatism is created by mass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miscibility Gap
A miscibility gap is a region in a phase diagram for a mixture of components where the mixture exists as two or more phases – any region of composition of mixtures where the constituents are not completely miscible. The IUPAC Gold Book defines ''miscibility gap'' as "Area within the coexistence curve of an isobaric phase diagram (temperature vs composition) or an isothermal phase diagram (pressure vs composition)." A miscibility gap between isostructural phases may be described as the ''solvus'', a term also used to describe the boundary on a phase diagram between a miscibility gap and other phases. Thermodynamically, miscibility gaps indicate a maximum (''e.g.'' of Gibbs energy) in the composition range. Named miscibility gaps A number of miscibility gaps in phase systems are named, including * The ''huttenlocher'' (found in bytownite, anorthite composition An55-95.), ''boggild'' (in labradorite, An39-48 and An53-63.) and peristerite (in oligoclase, ~An5-15.) miscibility g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Felsic
In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted with mafic rocks, which are relatively richer in magnesium and iron. Felsic refers to silicate minerals, magma, and rocks which are enriched in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. Felsic magma or lava is higher in viscosity than mafic magma/lava. Felsic rocks are usually light in color and have specific gravities less than 3. The most common felsic rock is granite. Common felsic minerals include quartz, muscovite, orthoclase, and the sodium-rich plagioclase feldspars (albite-rich). Terminology In modern usage, the term ''acid rock'', although sometimes used as a synonym, normally now refers specifically to a high-silica-content (greater than 63% SiO2 by weight) volcanic rock, such as rhyolite. Older, broader usage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kimberlite
Kimberlite is an igneous rock and a rare variant of peridotite. It is most commonly known to be the main host matrix for diamonds. It is named after the town of Kimberley in South Africa, where the discovery of an diamond called the Star of South Africa in 1869 spawned a diamond rush and the digging of the open-pit mine called the Big Hole. Previously, the term kimberlite has been applied to olivine lamproites as Kimberlite II, however this has been in error. Kimberlite occurs in the Earth's crust in vertical structures known as kimberlite pipes, as well as igneous dykes. Kimberlite also occurs as horizontal sills. Kimberlite pipes are the most important source of mined diamonds today. The consensus on kimberlites is that they are formed deep within the mantle. Formation occurs at depths between , potentially from anomalously enriched exotic mantle compositions, and they are erupted rapidly and violently, often with considerable carbon dioxide and other volatile componen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophanite
Pyrophanite is a manganese titanium oxide mineral with formula: MnTiO3. It is a member of the ilmenite group. It is a deep red to greenish black mineral which crystallizes in the trigonal system. Discovery and occurrence It was first described in 1890 from an occurrence in the Harstigen Mine, Filipstad, Värmland, Sweden. Its name was derived from the Greek ''πΰρ,'' fire, and ''φαίνεσθαι,'' to appear, because of the deep red color of the mineral. Its main occurrence is in manganese deposits that have undergone metamorphism. It also occurs in granite, amphibolite and serpentinite as an uncommon accessory mineral. Associated minerals include ilmenite, geikielite, hematite, spinel, gahnite, chromite, magnetite, ganophyllite, manganophyllite, hendricksite, garnet and calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geikielite
Geikielite is a magnesium titanium oxide mineral with formula: MgTiO3. It is a member of the ilmenite group. It crystallizes in the trigonal system forming typically opaque, black to reddish black crystals. It was first described in 1892 for an occurrence in the Ceylonese gem bearing gravel placers. It was named for Scottish geologist Sir Archibald Geikie (1835–1924). It occurs in metamorphosed impure magnesian limestones, in serpentinite derived from ultramafic rocks, in kimberlites and carbonatites. Associated minerals include rutile, spinel, clinohumite, perovskite, diopside, serpentine, forsterite, brucite, hydrotalcite, chlorite and calcite Calcite is a Carbonate minerals, carbonate mineral and the most stable Polymorphism (materials science), polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on .... References Further reading * * * * * * * * Oxide minerals Trigonal miner ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
