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Diaboleite
Diaboleite is a blue-colored mineral with formula Pb2CuCl2(OH)4. It was discovered in England in 1923 and named ''diaboleite'', from the Greek word διά and boleite, meaning "distinct from boleite". The mineral has since been found in a number of countries. Description Diaboleite is deep blue in color and pale blue in transmitted light. The mineral occurs as tabular crystals up to in size, as subparallel aggregates, or it has massive habit. Vicinal forms of the tabular crystals have a square or octagonal outline and rarely exhibit pyramidal hemihedralism. Formation Diaboleite occurs in manganese oxide ores, as a secondary mineral in lead and copper oxide ores, and in seawater-exposed slag. Diaboleite has been found in association with atacamite, boleite, caledonite, cerussite, chloroxiphite, hydrocerussite, leadhillite, mendipite, paratacamite, phosgenite, and wherryite. A study in 1986 synthesized diaboleite crystals up to in size using two different methods. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chloroxiphite
Chloroxiphite is a rare olive green to pistacio green lead copper halide mineral with formula: Pb3CuO2Cl2(OH)2. It was first discovered in 1923 in the Mendip Hills, Somerset, England associated with mendipite. Like mendipite it is an oxychloride mineral and formed from the alteration of lead ore (galena) by secondary oxidation. In addition to mendipite, it occurs with diaboleite, parkinsonite, wulfenite, cerussite and hydrocerussite. Its name comes from the Greek words (χλωρός) "green", describing its color, and (ζιφος) "blade" as its crystal A crystal or crystalline solid is a solid material whose constituents (such as atoms, molecules, or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macros ... form is long blade-like crystals that often show the growth pattern and time taken to form. References Lead minerals Copper(II) minerals Halide minerals Monoclinic mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boleite
Boleite is a complex halide mineral with formula: KPb26Ag9Cu24(OH)48Cl62. It was first described in 1891 as an oxychloride mineral. It is an isometric mineral which forms in deep-blue cubes. There are numerous minerals related to boleite, such as pseudoboleite, cumengite, and diaboleite, and these all have the same complex crystal structure. They all contain bright-blue cubic forms and are formed in altered zones of lead and copper deposits, produced during the reaction of chloride bearing solutions with primary sulfide minerals.Rouse, Roland C. (1973/01). “The Crystal Structure of boleite – A Mineral Containing Silver Atom Clusters”. ''Journal of Solid State Chemistry'' 6(1): 86-92/ref> Physical properties The external property of a boleite crystal structure indicates its cubic structure. It is classified under the isometric crystal class. Boleite has a perfect cleavage in the 01direction, and has a very dark glossy blue color with a light greenish-blue color streak. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonal Crystal System
In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base (''a'' by ''a'') and height (''c'', which is different from ''a''). Bravais lattices There are two tetragonal Bravais lattices: the primitive tetragonal and the body-centered tetragonal. The base-centered tetragonal lattice is equivalent to the primitive tetragonal lattice with a smaller unit cell, while the face-centered tetragonal lattice is equivalent to the body-centered tetragonal lattice with a smaller unit cell. Crystal classes The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumengeite
Cumengeite, also known as cumengite, is a secondary mineral that was named after mining engineer Bernard Louis Philippe Édouard Cumenge, who found the first specimens. It is easily confused with diaboleite. It is a valid species that was first described prior to 1959, and is grandfathered now, but it has been a valid species since 1893, since pre- IMA. It is the hydroxychloride of lead and copper. Properties It is brittle and conchoidal, meaning it is easily breakable, and the fracture of it makes small, conchoidal fragments. It is an epitaxial mineral, which is a form of crystal growth. During the growth, the new crystalline layers are formed with at least one well-defined orientation. The crystal itself is pseudo-cubic, meaning its shape resembles that of a cube. When this uncommon mineral forms epitaxial overgrowths with boleite however, where the inner cubic core is boleite, and the outer protruding mineral which forms in triangular shape is cumengeite, the two mineral form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendipite
Mendipite is a rare mineral that was named in 1939 for the locality where it is found, the Mendip Hills in Somerset, England. It is an oxyhalide of lead with formula Pb3Cl2O2. Crystal structure Most references assert that mendipite crystallises in the orthorhombic crystal system, disphenoidal class 2 2 2, meaning that it has three mutually perpendicular axes of twofold symmetry, with space group P212121, meaning that each of these axes is a screw axis. One reference, however, gives the crystal class as orthorhombic m m m with space group Pnma, which has a higher symmetry. In each case the "P" means that the mineral has a primitive unit cell. Unit cell parameters: * a = 9.52 Å, b = 11.87 Å, c = 5.87 Å, Z = 4 * a = 11.87 Å, b = 5.806 Å, c = 9.48 Å, Z = 4 Optical properties Mendipite is colorless to white, brownish cream, grey, yellowish, pink, red, or blue. It is nearly colorless in transmitted light. It has a white streak and its luster is pearly to silky on cleavag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halide Mineral
Halide minerals are those minerals with a dominant halide anion (, , and ). Complex halide minerals may also have polyatomic anions. Examples include the following: * Atacamite *Avogadrite (K,Cs)BF *Bararite (β) *Bischofite * Brüggenite * Calomel * Carnallite * Carnallite *Cerargyrite/ Horn silver AgCl * Chlorargyrite AgCl, bromargyrite AgBr, and iodargyrite AgI * Cryolite * Cryptohalite (a) . * Dietzeite * Eglestonite * Embolite AgCl+AgBr * [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Mineralogical Association
Founded in 1958, the International Mineralogical Association (IMA) is an international group of 40 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 5000 plus known mineral species. The IMA is affiliated with the International Union of Geological Sciences (IUGS). The Association supports the activities of Commissions and Working Groups involved on certain aspects of mineralogical practice and facilitates interactions among mineralogists by sponsoring and organising meetings. In particular, the IMA holds its general meeting every four years. The next meeting is scheduled in 2022 in Lyon, France. Presidents The presidents of the IMA have been: * since 2021: Anhuai Lu ** Peking University *2018–2020: Patrick Cordier (born 1961) ** Université de Lille *2016–2018: Peter C. Burns ** University of Notre Dame *2014–2016: Sergey V. Krivovichev (born 1972) ** Saint Petersburg State University *2012–2014: Walter V. Mar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grandfathered
A grandfather clause, also known as grandfather policy, grandfathering, or grandfathered in, is a provision in which an old rule continues to apply to some existing situations while a new rule will apply to all future cases. Those exempt from the new rule are said to have grandfather rights or acquired rights, or to have been grandfathered in. Frequently, the exemption is limited, as it may extend for a set time, or it may be lost under certain circumstances; for example, a grandfathered power plant might be exempt from new, more restrictive pollution laws, but the exception may be revoked and the new rules would apply if the plant were expanded. Often, such a provision is used as a compromise or out of practicality, to allow new rules to be enacted without upsetting a well-established logistical or political situation. This extends the idea of a rule not being retroactively applied. Origin Southern United States The term originated in late nineteenth-century legislation and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somerset
( en, All The People of Somerset) , locator_map = , coordinates = , region = South West England , established_date = Ancient , established_by = , preceded_by = , origin = , lord_lieutenant_office =Lord Lieutenant of Somerset , lord_lieutenant_name = Mohammed Saddiq , high_sheriff_office =High Sheriff of Somerset , high_sheriff_name = Mrs Mary-Clare Rodwell (2020–21) , area_total_km2 = 4171 , area_total_rank = 7th , ethnicity = 98.5% White , county_council = , unitary_council = , government = , joint_committees = , admin_hq = Taunton , area_council_km2 = 3451 , area_council_rank = 10th , iso_code = GB-SOM , ons_code = 40 , gss_code = , nuts_code = UKK23 , districts_map = , districts_list = County council area: , MPs = * Rebecca Pow (C) * Wera Hobhouse ( LD) * Liam Fox (C) * David Warburton (C) * Marcus Fysh (C) * Ian Liddell-Grainger (C) * James Heappey (C) * Jacob Rees-Mogg (C) * John Penrose (C) , police = Avon and Somerset Polic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mendip Hills
The Mendip Hills (commonly called the Mendips) is a range of limestone hills to the south of Bristol and Bath in Somerset, England. Running from Weston-super-Mare and the Bristol Channel in the west to the Frome valley in the east, the hills overlook the Somerset Levels to the south and the Chew Valley and other tributaries of the Avon to the north. The hills give their name to the local government district of Mendip, which administers most of the area. The higher, western part of the hills, covering has been designated an Area of Outstanding Natural Beauty (AONB), which gives it a level of protection comparable to a national park. The hills are largely formed from Carboniferous Limestone, which is quarried at several sites. Ash–maple woodland, calcareous grassland and mesotrophic grassland which can be found across the Mendip Hills provide nationally important semi-natural habitats. With their temperate climate these support a range of flora and fauna including birds, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal
Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with the assistance of. Roderick McKenzie.'' Oxford: Clarendon Press. and θέρμη, ''heat'' ). Hydrothermal circulation occurs most often in the vicinity of sources of heat within the Earth's crust. In general, this occurs near volcanic activity, but can occur in the shallow to mid crust along deeply penetrating fault irregularities or in the deep crust related to the intrusion of granite, or as the result of orogeny or metamorphism. Seafloor hydrothermal circulation Hydrothermal circulation in the oceans is the passage of the water through mid-oceanic ridge systems. The term includes both the circulation of the well-known, high-temperature vent waters near the ridge crests, and the much-lower-temperature, diffuse flow of water through sed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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