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Arsenical Bronze
Arsenical bronze is an alloy in which arsenic, as opposed to or in addition to tin or other constituent metals, is combined with copper to make bronze. The use of arsenic with copper, either as the secondary constituent or with another component such as tin, results in a stronger final product and better casting behavior. Copper ore is often naturally contaminated with arsenic; hence, the term "arsenical bronze" when used in archaeology is typically only applied to alloys with an arsenic content higher than 1% by weight, in order to distinguish it from potentially accidental additions of arsenic. Origins in pre-history Although arsenical bronze occurs in the archaeological record across the globe, the earliest artifacts so far known, dating from the 5th millennium BC, have been found on the Iranian plateau. Arsenic is present in a number of copper-containing ores (see table at right, adapted from Lechtman & Klein, 1999), and therefore some contamination of the copper with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thai - Seated Buddha In "Maravijaya" - Walters 542742
Thai or THAI may refer to: * Of or from Thailand, a country in Southeast Asia. ** Thai people, Siamese people, Central/Southern Thai people or Thai noi people, an ethnic group from Central and Southern Thailand. ** , Thai minority in southern Myanmar. ** , Bamar with Thai ancestry in Central Myanmar. ** Sukhothai language, a kind of Southwestern Tai languages, Thai topolect, by the end of the 18th century, they gradually diverged into regional variants, which subsequently developed into the modern Central Thai and Southern Thai. *** Thai language, Central Thai language or Siamese language, the sole official language in Thailand and first language of most people in Central Thailand, including Thai Chinese in Southern Thailand. *** Southern Thai language, or Southern Siamese language, or Tambralinga language, language of Southern Thailand first language of most people in Southern Thailand *** Thai script *** Thai (Unicode block) People with the name * Thai (surname), a Vietnamese ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iranian Plateau
The Iranian plateau or Persian plateau is a geological feature spanning parts of the Caucasus, Central Asia, South Asia, and West Asia. It makes up part of the Eurasian plate, and is wedged between the Arabian plate and the Indian plate. The plateau is situated between the Zagros Mountains to the west, the Caspian Sea and the Köpet Dag to the north, the Armenian Highlands and the Caucasus Mountains to the northwest, the Strait of Hormuz and the Persian Gulf to the south, and the Indian subcontinent to the southeast. As a historical region, it includes Parthia, Media, Persis, and some of the previous territories of Greater Iran."Old Iranian Online" , University of Texas College of Liberal Arts (retrieved 10 February 2007) The Zagros form the plateau's western boundary, and its eastern slopes may also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enargite
Enargite is a copper arsenic sulfosalt mineral with formula Cu3AsS4. It takes its name from the Greek word , "distinct". Enargite is a steel gray, blackish gray, to violet black mineral with metallic luster. It forms slender orthorhombic prisms as well as massive aggregates. It has a hardness of 3 and a specific gravity of 4.45. Enargite is dimorph of the tetragonal luzonite. Occurrence It is a medium to low temperature hydrothermal mineral occurring with quartz, pyrite, sphalerite, galena, bornite, tetrahedrite–tennantite, chalcocite, covellite and baryte. It occurs in the mineral deposits at Butte, Montana, San Juan Mountains, Colorado and at both Bingham Canyon and Tintic, Utah. It is also found in the copper mines of Canada, Mexico, Argentina, Chile, Peru, and the Philippines. Enargite was originally described as a new species from the copper mines of the San Francisco vein, Junin Department, Peru Peru, officially the Republic of Peru, is a country in west ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fahlore
Fahlore, or Fahlerz, refers to an ore consisting of complex sulfosalts, mostly the series between tennantite and tetrahedrite . It comes from the German word for pale, '. This refers to the characteristic pale grey to dark black colour. References {{mineral-stub Sulfide minerals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Copper Arsenate
Copper arsenate (Cu3(AsO4)2·4H2O, or Cu5H2(AsO4)4·2H2O), also called copper orthoarsenate, tricopper arsenate, cupric arsenate, or tricopper orthoarsenate, is a blue or bluish-green powder insoluble in water and alcohol and soluble in aqueous ammonium and dilute acids. Uses Copper arsenate is an insecticide used in agriculture. It is also used as a herbicide, fungicide, and a rodenticide. It is also used as a poison in slug baits. Copper arsenate can also be a misnomer for copper arsenite, especially when meant as a pigment A pigment is a powder used to add or alter color or change visual appearance. Pigments are completely or nearly solubility, insoluble and reactivity (chemistry), chemically unreactive in water or another medium; in contrast, dyes are colored sub .... Natural occurrences Anhydrous copper arsenate, Cu3(AsO4)2, is found in nature as the mineral lammerite. Copper arsenate tetrahydrate, Cu3(AsO4)2·4H2O, occurs naturally as the mineral rollandite. Related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimony
Antimony is a chemical element; it has chemical symbol, symbol Sb () and atomic number 51. A lustrous grey metal or metalloid, it is found in nature mainly as the sulfide mineral stibnite (). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name Kohl (cosmetics), kohl. The earliest known description of this metalloid in the West was written in 1540 by Vannoccio Biringuccio. China is the largest producer of antimony and its compounds, with most production coming from the Xikuangshan Mine in Hunan. The industrial methods for refining antimony from stibnite are Roasting (metallurgy), roasting followed by carbothermic reaction, reduction with carbon, or direct reduction of stibnite with iron. The most common applications for metallic antimony are in alloys with lead and tin, which have improved properties for solders, Bullet, bullets, and plain bearings. It improves the rigidity of lead-alloy pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redox
Redox ( , , reduction–oxidation or oxidation–reduction) is a type of chemical reaction in which the oxidation states of the reactants change. Oxidation is the loss of electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. The oxidation and reduction processes occur simultaneously in the chemical reaction. There are two classes of redox reactions: * Electron transfer, Electron-transfer – Only one (usually) electron flows from the atom, ion, or molecule being oxidized to the atom, ion, or molecule that is reduced. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * Atom transfer – An atom transfers from one Substrate (chemistry), substrate to another. For example, in the rusting of iron, the oxidation state of iron atoms increases as the iron converts to an oxide, and simultaneously, the oxidation state of oxygen decreases as it accepts electrons r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Realgar
Realgar ( ), also known as arsenic blende, ruby sulphur or ruby of arsenic, is an arsenic sulfide mineral with the chemical formula α-. It is a soft, sectile mineral occurring in monoclinic crystals, or in granular, compact, or powdery form, often in association with the related mineral, orpiment (). It is orange-red in color, melts at 320 °C, and burns with a bluish flame releasing fumes of arsenic and sulfur. Realgar is soft with a Mohs hardness of 1.5 to 2 and has a specific gravity of 3.5. Its streak is orange colored. It is trimorphous with pararealgar and bonazziite. Etymology Its name comes from the Arabic ''rahj al-ġār'' ( , "powder of the mine"), via Medieval Latin, and its earliest record in English is in the 1390s. Uses Realgar is a minor ore of arsenic extracted in China, Peru, and the Philippines. Historical uses Realgar was used by firework manufacturers to create the color white in fireworks prior to the availability of powdered metals such as al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most abundant element in the Earth's crust, being mainly deposited by meteorites in its metallic state. Extracting usable metal from iron ores requires kilns or furnaces capable of reaching , about 500 °C (900 °F) higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BC and the use of iron tools and weapons began to displace copper alloys – in some regions, only around 1200 BC. That event is considered the transition from the Bronze Age to the Iron Age. In the modern world, iron alloys, such as steel, stainless steel, cast iron and special steels, are by far the most common industrial metals, due to their mechan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tennantite
Tennantite is a copper arsenic sulfosalt mineral with an ideal formula . Due to variable substitution of the copper by iron and zinc the formula is . It is gray-black, steel-gray, iron-gray or black in color. A closely related mineral, tetrahedrite ) has antimony substituting for arsenic and the two form a solid solution series. The two have very similar properties and is often difficult to distinguish between tennantite and tetrahedrite. Iron, zinc, and silver substitute up to about 15% for the copper site. The mineral was first described for an occurrence in Cornwall, England in 1819, where it occurs as small crystals of cubic or dodecahedral form, and was named after the English chemist Smithson Tennant (1761–1815). It is found in hydrothermal veins and contact metamorphic deposits in association with other Cu–Pb–Zn–Ag sulfides and sulfosalts, pyrite, calcite, dolomite, siderite, barite, fluorite and quartz. The arsenic component of tennantite causes the metal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Native Copper
Native copper is an uncombined form of copper that occurs as a natural mineral. Copper is one of the few metallic elements to occur in native form, although it most commonly occurs in oxidized states and mixed with other elements. Native copper was an important ore used by pre-historic peoples. The name copper comes from the Greek ''kyprios'', "of Cyprus", the location of native copper mines since pre-historic times. Native copper typically occurs as irregular masses and fracture fillings, and rarely as isometric cubic and octahedral crystals. It has a reddish, orangish, and/or brownish color on fresh surfaces, but typically is weathered to a state of verdigris and coated with a green or blue-green tarnish or patina of copper(II) carbonate. Its specific gravity is 8.9 and Mohs hardness is 2.5–3. The mines of the Keweenaw native copper deposits of Upper Michigan were major copper producers in the 19th and early 20th centuries, and are the largest deposits of native co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelting
Smelting is a process of applying heat and a chemical reducing agent to an ore to extract a desired base metal product. It is a form of extractive metallurgy that is used to obtain many metals such as iron-making, iron, copper extraction, copper, silver mining#Ore processing, silver, tin, lead smelting, lead and zinc smelting, zinc. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal behind. The reducing agent is commonly a fossil-fuel source of carbon, such as carbon monoxide from incomplete combustion of coke (fuel), coke—or, in earlier times, of charcoal. The oxygen in the ore binds to carbon at high temperatures, as the Chemical energy, chemical potential energy of the bonds in carbon dioxide () is lower than that of the bonds in the ore. Sulfide ores such as those commonly used to obtain copper, zinc or lead, are roasting (metallurgy), roasted before smelting in order to convert the sulfid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
