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Penfieldite
Penfieldite is a rare lead hydroxychloride mineral from the class of halides. It was named after Samuel Lewis Penfield. It has been a valid species before the founding of IMA, and was first published in 1892. It had been grandfathered, meaning the name penfieldite is still believed to refer to a valid species. When it was first described by Genth in 1892 from Laurion, Greece, the mineral had the formula of Pb3Cl4O. Properties Penfieldite grows tabular pyramidal crystals, meaning it is longer instead of being wide, and grows in the shape of a pyramid. It is a secondary mineral, meaning that rock minerals went under transformation due to changes in pressure and temperature, and penfieldite is the newly formed stable mineral after this transformation. Singular crystals are usually striped, and can grow up to 3 cm. Pure penfieldite is colorless, however, due to lattice defects or foreign admixtures, it can be white, yellow or even blue. It mainly consists of lead (77.06%) and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexagonal
In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A '' regular hexagon'' has Schläfli symbol and can also be constructed as a truncated equilateral triangle, t, which alternates two types of edges. A regular hexagon is defined as a hexagon that is both equilateral and equiangular. It is bicentric, meaning that it is both cyclic (has a circumscribed circle) and tangential (has an inscribed circle). The common length of the sides equals the radius of the circumscribed circle or circumcircle, which equals \tfrac times the apothem (radius of the inscribed circle). All internal angles are 120 degrees. A regular hexagon has six rotational symmetries (''rotational symmetry of order six'') and six reflection symmetries (''six lines of symmetry''), making up the dihedral group D6. The longest diagonals of a regular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead Hydroxychloride
Lead is a chemical element with the symbol Pb (from the Latin ) and atomic number 82. It is a heavy metal that is denser than most common materials. Lead is soft and malleable, and also has a relatively low melting point. When freshly cut, lead is a shiny gray with a hint of blue. It tarnishes to a dull gray color when exposed to air. Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements. Lead is toxic, even in small amounts, especially to children. Lead is a relatively unreactive post-transition metal. Its weak metallic character is illustrated by its amphoteric nature; lead and lead oxides react with acids and bases, and it tends to form covalent bonds. Compounds of lead are usually found in the +2 oxidation state rather than the +4 state common with lighter members of the carbon group. Exceptions are mostly limited to organolead compounds. Like the lighter members of the group, le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Lewis Penfield
Samuel Lewis Penfield (January 16, 1856 – August 12, 1906) was an American analytic chemist, mineralologist, and crystallographer who first obtained the chemical structures of more than two dozen naturally occurring minerals."Samuel Lewis Penfield", Science, vol. 24, issue 608, p. 252 (August, 1906) Biography Penfield prepared for college at the Catskill Academy and the academy at Wilbraham, Massachusetts. He matriculated at Yale in the Sheffield Scientific School in 1873, graduating with honors in 1877 and becoming a scientific assistant in chemistry and in mineralology. Except for brief periods abroad, in Germany (where he trained in crystallography), his entire subsequent career was to be at Yale. In early work, He analyzed the then-new so-called Branchville phosphates, fairfieldite and fillowite, as well as samples of chabazite and rhodocrosite from the same locality. He was soon known as expert in analyzing minerals containing fluorine. Penfield became assistant professor o ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Mineral
A primary mineral is any mineral formed during the original crystallization of the host igneous primary rock and includes the essential mineral(s) used to classify the rock along with any accessory minerals. In ore deposit geology, hypogene processes occur deep below the Earth's surface, and tend to form deposits of primary minerals, as opposed to supergene processes that occur at or near the surface, and tend to form secondary minerals. The elemental and mineralogical composition of primary rocks is determined by the chemical composition of the volcanic or magmatic flow from which it is formed. Extrusive rocks (such as basalt, rhyolite, andesite and obsidian) and intrusive rocks (such as granite, granodiorite, gabbro and peridotite) contain primary minerals including quartz, feldspar, plagioclase, muscovite, biotite, amphibole, pyroxene and olivine in varying concentrations. Additionally, primary sulfate minerals occur in igneous rocks. Primary sulfate minerals may occur in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strunz Mineralogical Tables , a band
{{Disambig, surname ...
Strunz can refer to: * Claudio Strunz (born 1966), Argentine drummer * Claus Strunz (born 1966), German journalist * Thomas Strunz, (born 1968), German soccer player * Strunz classification in mineralogy * Strunz & Farah Strunz & Farah is a guitar duo with an eclectic sound that has been described as a cross between world fusion and flamenco. History Jorge Strunz, born in Costa Rica, and Ardeshir Farah, hailing from Iran, met in the United States in 1979. Jo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baratti Beach, Italy
Baratti may refer to: Place *Baratti (town) Baratti is a village ''frazione'' of the comune of Piombino in the Province of Livorno, with roughly only 15 residents. History Just like its neighbour Populonia, Baratti has Etruscan origins, confirmed by various burial mounds found around the ar ..., town in Italy * Baratti and Populonia Archeological Park, Park in the province of Livorno in Italy People * Antonio Baratti, (1724-1787), Italian engraver * Boris de Rachewiltz (redirect from Boris Baratti), Italian Egyptologist * Éva Barati (born 1968 in Üröm) is a Hungarian athlete See also * Barati (other) {{Disambiguation, geo, surname ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Margarita Mine, Chile
A margarita is a cocktail consisting of Tequila, triple sec, and lime juice often served with salt on the rim of the glass. The drink is served shaken with ice (on the rocks), blended with ice (frozen margarita), or without ice (straight up). The drink is generally served in a stepped-diameter variant of a cocktail glass or champagne coupe called a margarita glass. Origin The history of the margarita is one of folklore due to its numerous origin stories. According to cocktail historian David Wondrich, the margarita is related to the brandy daisy (''margarita'' is Spanish for "daisy"), remade with tequila instead of brandy. (Daisies are a family of cocktails that include a base spirit, liqueur, and citrus. A sidecar and gin daisy are other related drinks.) There is an account from 1936 of Iowa newspaper editor James Graham finding such a cocktail in Tijuana, years before any of the other margarita "creation myths". The ''Cafe Royal Cocktail Book'', published in the UK in 1937, c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosgenite
Phosgenite is a rare mineral consisting of lead chlorocarbonate, (PbCl)2CO3. The tetragonal crystals are prismatic or tabular in habit: they are usually colorless and transparent, and have a brilliant adamantine lustre. Sometimes the crystals have a curious helical twist about the tetrad or principal axis. The hardness is 3 and the specific gravity 6.3. The mineral is rather sectile, and consequently was earlier known as corneous lead, (German ''Hornblei''). Name and occurrence The name phosgenite was given by August Breithaupt in 1820, from phosgene, carbon oxychloride, because the mineral contains the elements carbon, oxygen and chlorine. It was found associated with anglesite and matlockite in cavities within altered galena in a lead mine at Cromford, near Matlock: hence its common name cromfordite. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paralaurionite
Paralaurionite is a colorless mineral consisting of a basic lead chloride PbCl(OH) that is dimorphous with laurionite. It is a member of the matlockite group. The name is derived from para-, the Greek for "near", and laurionite, because of its polymorphic relationship to it. Bright, yellow tips of thorikosite can form on paralaurionite crystals and paralaurionite may also be intergrown with mendipite. Occurrence It was first described in 1899 for an occurrence in slag in Laurium, Attica, Greece. In 1952 an occurrences of it was reported from the Mammoth Mine, Arizona. It occurs in lead bearing slag which has been exposed to seawater. It also occurs in polymetallic ore deposits. It occurs associated with laurionite, penfieldite, fiedlerite, phosgenite in slag deposits; and with leadhillite, matlockite, cerussite, hydrocerussite, diaboleite Diaboleite is a blue-colored mineral with formula Pb2CuCl2(OH)4. It was discovered in England in 1923 and named ''diaboleite'', from the Gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
