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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 Combrailles. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
City
A city is a human settlement of a substantial size. The term "city" has different meanings around the world and in some places the settlement can be very small. Even where the term is limited to larger settlements, there is no universally agreed definition of the lower boundary for their size. In a narrower sense, a city can be defined as a permanent and Urban density, densely populated place with administratively defined boundaries whose members work primarily on non-agricultural tasks. Cities generally have extensive systems for housing, transportation, sanitation, Public utilities, utilities, land use, Manufacturing, production of goods, and communication. Their density facilitates interaction between people, government organisations, government organizations, and businesses, sometimes benefiting different parties in the process, such as improving the efficiency of goods and service distribution. Historically, city dwellers have been a small proportion of humanity overall, bu ... [...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 Mohs scale, hardness of 3.5 to 4 on the Mohs scale. Its Streak (mineralogy), 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). It is rarely found in association with native copper. Chalcopyrite is a conductor of electricity. Copper can be extracted from chalcopyrite ore using various methods. The two predominant methods are pyrometallurgy and hydrometallurgy, the former being the most commercially viable. Etymology The name chalcopyrite comes from the Greek words , which means cop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puy De Dôme
Puy de Dôme (, ) 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. It is approximately from Clermont-Ferrand. The Puy-de-Dôme is named after the volcano. History In pre-Christian Europe, Puy de Dôme was 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 1872. In 1648, , at the urging of his brother-in-law Blaise Pascal, confirmed 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, a TDF () antenna is also located there. On th ... [...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. Archaeology Initial discovery and research file:Temple de Mercure, Observatoire du Puy-de-DômeVers1900.jpg, left, The temple and observatory, around 1900 The site was discovered in 1872 during the construction of a observatory, 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 p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wulfenite
Wulfenite is a lead molybdate mineral with the formula Pb Mo O4. It often occurs 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 Xaver 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, pyromorph ... [...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 c ... [...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 is 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 England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers abou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphalerite
Sphalerite 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 black variety with a high iron ... [...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 Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of Silicon dioxide, SiO2. Quartz is, therefore, classified structurally as a Silicate mineral#Tectosilicates, framework silicate mineral and compositionally as an oxide mineral. 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 classifi ... [...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. Pyromorphite is part of the apatite group of minerals and bears a close resemblance physically and chemically 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''). History The mineral was first distinguished chemically by M. H. Klaproth in 1784, and it was named pyromorphite by J. F. L. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
