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Société Des Mines Et Fonderies De Pontgibaud
The Société des mines et fonderies de Pontgibaud (Pontgibaud Mine & Foundry Company) was a French silver and lead mining and smelting company based in Pontgibaud, Puy-de-Dôme. It mined lead-silver ore deposits that had been exploited since Roman times. Later it opened another factory in Couëron in the Loire estuary, and then closed down the Pontgibaud mines and foundry. The Pontgibaud factory in Couëron diversified into other non-ferrous metal products using imported ore. After being sold and resold it finally closed in 1988. Location Pontgibaud is in the Massif Central on the banks of the Sioule river. The belts of ore extend for about north-south parallel to the course of the Sioule on both sides of Pontgibaud. The silver galena veins are embedded in gneissic rock. The different veins of ore at Pranal, Barbecot, Roure, Les Rosiers, La Miouse and Villevieille are mainly oriented in a north-south direction. The ores are encased in migmatites from the base of the Combraille ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
City
A city is a human settlement of notable size.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge. It can be defined as a permanent and densely settled place with administratively defined boundaries whose members work primarily on non-agricultural tasks. Cities generally have extensive systems for housing, transportation, sanitation, utilities, land use, production of goods, and communication. Their density facilitates interaction between people, government organisations and businesses, sometimes benefiting different parties in the process, such as improving efficiency of goods and service distribution. Historically, city-dwellers have been a small proportion of humanity overall, but following two centuries of unprecedented and rapid urbanization, more than half of the world population now lives in cities, which has had profound consequences for g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chalcopyrite
Chalcopyrite ( ) is a copper iron sulfide mineral and the most abundant copper ore mineral. It has the chemical formula CuFeS2 and crystallizes in the tetragonal system. It has a brassy to golden yellow color and a hardness of 3.5 to 4 on the Mohs scale. Its streak is diagnostic as green-tinged black. On exposure to air, chalcopyrite tarnishes to a variety of oxides, hydroxides, and sulfates. Associated copper minerals include the sulfides bornite (Cu5FeS4), chalcocite (Cu2S), covellite (CuS), digenite (Cu9S5); carbonates such as malachite and azurite, and rarely oxides such as cuprite (Cu2O). Is rarely found in association with native copper. Chalcopyrite is a conductor of electricity. Etymology The name chalcopyrite comes from the Greek words , which means copper, and ', which means striking fire. It was sometimes historically referred to as "yellow copper". Identification Chalcopyrite is often confused with pyrite and gold since all three of these minerals have a yell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puy De Dôme
Puy de Dôme (, ; oc, label=Auvergnat, Puèi Domat or ) is a lava dome and one of the youngest volcanoes in the region of Massif Central in central France. This chain of volcanoes including numerous cinder cones, lava domes and maars is far from the edge of any tectonic plate. Puy de Dôme was created by a Peléan eruption, some 10,700 years ago. Puy de Dôme is approximately from Clermont-Ferrand. The Puy-de-Dôme is named after the volcano. History In pre-Christian Europe, Puy de Dôme served as an assembly place for spiritual ceremonies. Temples were built at the summit, including a Gallo-Roman temple of Mercury, the ruins of which were discovered in 1873. In 1648, Florin Périer, at the urging of Blaise Pascal, supported Evangelista Torricelli's theory that barometric observations were caused by the weight of air by measuring the height of a column of mercury at three elevations on Puy de Dôme. In 1875, a physics laboratory was built at the summit. Since 1956, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temple Of Mercury (Puy De Dôme)
The Temple of Mercury at Puy de Dôme is a Gallo-Roman trachyte temple built in the 2nd century at the summit of the lava dome. It replaced a 1st-century arkose temple on the same site, which was apparently too small to accommodate the many pilgrims who visited. Its remains were revealed by excavation campaigns in 1875 and at the turn of the century. Archaeological History Initial Discovery and Research left, The temple and observatory, around 1900 The site was discovered in 1872 during the construction of a meteorological observatory. Very quickly, the first excavations took place between 1873 and 1878, conducted by The Academy of Sciences of Clermont-Ferrand, under Louis-Clémentin Bruyère's direction in 1875. This initial research made it possible to conceive of the first site plans. The excavations were then stopped and the temple abandoned in that state. It was not until 1886 that steps were taken to protect it. It was classified as a historic monument in 1889. A numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wulfenite
Wulfenite is a lead molybdate mineral with the formula Pb Mo O4. It can be most often found as thin tabular crystals with a bright orange-red to yellow-orange color, sometimes brown, although the color can be highly variable. In its yellow form it is sometimes called "yellow lead ore". It crystallizes in the tetragonal system, often occurring as stubby, pyramidal or tabular crystals. It also occurs as earthy, granular masses. It is found in many localities, associated with lead ores as a secondary mineral associated with the oxidized zone of lead deposits. It is also a secondary ore of molybdenum, and is sought by collectors. Discovery and occurrence Wulfenite was first described in 1845 for an occurrence in Bad Bleiberg, Carinthia, Austria. It was named for Franz Xavier von Wulfen (1728–1805), an Austrian mineralogist. It occurs as a secondary mineral in oxidized hydrothermal lead deposits. It occurs with cerussite, anglesite, smithsonite, hemimorphite, vanadinite, pyromor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedrite
Tetrahedrite is a copper antimony sulfosalt mineral with formula: . It is the antimony endmember of the continuous solid solution series with arsenic-bearing tennantite. Pure endmembers of the series are seldom if ever seen in nature. Of the two, the antimony rich phase is more common. Other elements also substitute in the structure, most notably iron and zinc, along with less common silver, mercury and lead. Bismuth also substitutes for the antimony site and ''bismuthian tetrahedrite'' or ''annivite'' is a recognized variety. The related, silver dominant, mineral species freibergite, although rare, is notable in that it can contain up to 18% silver. Mineralogy Tetrahedrite gets its name from the distinctive tetrahedron shaped cubic crystals. The mineral usually occurs in massive form, it is a steel gray to black metallic mineral with Mohs hardness of 3.5 to 4 and specific gravity of 4.6 to 5.2. Tetrahedrite occurs in low to moderate temperature hydrothermal veins and in some co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stannite
Stannite is a mineral, a sulfide of copper, iron, and tin, in the category of thiostannates. Background The chemical formula Cu2 Fe Sn S4. Zinc commonly occurs with the iron and trace germanium may be present. Stannite is used as an ore of tin, consisting of approximately 28% tin, 13% iron, 30% copper, 30% sulfur by mass. It is found in tin-bearing, hydrothermal vein deposits occurring with chalcopyrite, sphalerite, tetrahedrite, arsenopyrite, pyrite, cassiterite, and wolframite. It is also known as ''bell metal ore'' as tin is an important constituent of bell-metal. It is thought the exploitation of tin deposits in Cornwall led to an expansion in bell founding. The name comes from the Latin for tin: ''stannum''. It was first described in 1797 for an occurrence in Wheal Rock, St. Agnes, Cornwall, England. See also * Kesterite Kësterite is a sulfide mineral with a chemical formula of . In its lattice structure, zinc and iron atoms share the same lattice sites. Kesterit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphalerite
Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula . It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in Sedimentary exhalative deposits, sedimentary exhalative, Carbonate-hosted lead-zinc ore deposits, Mississippi-Valley type, and Volcanogenic massive sulfide ore deposit, volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfide mineral, sulfides), calcite, dolomite (mineral), dolomite, quartz, rhodochrosite, and fluorite. German geologist Ernst Friedrich Glocker discovered sphalerite in 1847, naming it based on the Greek word ''sphaleros'', meaning "deceiving", due to the difficulty of identifying the mineral. In addition to zinc, sphalerite is an ore of cadmium, gallium, germanium, and indium. Miners have been known to refer to sphalerite as ''zinc blende'', ''black-jack'', and ''ruby blende''. Marmatite is an opaque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semseyite
Semseyite is a rarely occurring sulfosalt mineral and is part of the class of lead antimony sulfides. It crystallizes in the monoclinic system with the chemical composition Pb9Sb8S21. The mineral forms dark gray to black aggregates. Etymology and history Semseyite was first described for an occurrence in the Felsöbánya mine in Baia Sprie, Romania in 1881 by József Sándor Krenner (1839–1920). The mineral was named after Hungarian mineralogist Andor von Semsey (1833–1923). Occurrence Semseyite forms in hydrothermal solutions at temperatures between 300 and 350 °C.Andreas Kamrath: “Geology and mineralogy of ore stores Herja” It occurs in association with |
Quartz
Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar. Quartz exists in two forms, the normal α-quartz and the high-temperature β-quartz, both of which are chiral. The transformation from α-quartz to β-quartz takes place abruptly at . Since the transformation is accompanied by a significant change in volume, it can easily induce microfracturing of ceramics or rocks passing through this temperature threshold. There are many different varieties of quartz, several of which are classified as gemstones. Since antiquity, varieties of quartz have been the most commonly used minerals in the making of jewelry and hardstone carvings, especially in Eurasia. Quartz is the mineral defining the val ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyromorphite
Pyromorphite is a mineral species composed of lead chlorophosphate: Pb5( P O4)3 Cl, sometimes occurring in sufficient abundance to be mined as an ore of lead. Crystals are common, and have the form of a hexagonal prism terminated by the basal planes, sometimes combined with narrow faces of a hexagonal pyramid. Crystals with a barrel-like curvature are not uncommon. Globular and reniform masses are also found. It is part of a series with two other minerals: mimetite (Pb5( AsO4)3Cl) and vanadinite (Pb5( VO4)3Cl), the resemblance in external characters is so close that, as a rule, it is only possible to distinguish between them by chemical tests. They were formerly confused under the names green lead ore and brown lead ore (''German: Grünbleierz and Braunbleierz''). The phosphate was first distinguished chemically by M. H. Klaproth in 1784, and it was named pyromorphite by J. F. L. Hausmann in 1813. The name is derived from the Greek for ''pyr'' (fire) and ''morfe'' (form) due to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
