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Arsenic 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 arse ... [...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, the dominant ethnic group of Thailand ** Thai language, a Tai-Kadai language spoken mainly in and around Thailand *** Thai script *** Thai (Unicode block) People with the name * Thai (surname), a Vietnamese version of Cai, including a list of people with the name * Thai Lee (born 1958), an American businesswoman * Thai Nguyen, US-based Vietnamese fashion designer and television personality Other uses * Thai (cannabis), a name for the drug * Thai Airways, the national airline of Thailand * Thai cat, a breed of cat * Thai, a month in the Tamil calendar * Toe to Heel Air Injection (THAI), a method of extracting oil from oil sands See also * * Dai (other) * Tai (other) * Tay (other) * Thais (other) * Thay (other) * Tie (other) * Siam (other) * Tai peoples or Thai peoples, the ethnic groups of southern China and Southeast As ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iranian Plateau
The Iranian plateau or Persian plateau is a geological feature in Western Asia, Central Asia, and South Asia. It comprises part of the Eurasian Plate and is wedged between the Arabian Plate and the Indian Plate; 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 east. 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 be included in the term. The '' |
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 , image_flag = Flag of Peru.svg , image_coat ... [...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 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, ... . It comes from the German word for pale, ''fahl''. This refers to the characteristic pale grey to dark black colour. References Sulfide minerals {{mineral-stub ... [...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. Its CAS number is or . 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. 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 compounds Copper arsenate hydroxide or basic copper arsenate (Cu(OH)AsO4) is a basic variant with CAS number . It is found naturally as the mineral olivenite. It is used as an insecticide, fungicide, and miticide. Its use is banned ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimony
Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl. The earliest known description of the metal 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 followed by reduction with carbon, or direct reduction of stibnite with iron. The largest applications for metallic antimony are in alloys with lead and tin, which have improved properties for solders, bullets, and plain bearings. It improves the rigidity of lead-alloy plates in lead–acid batteries. Antimony trioxide is a prominent additive for halo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Redox
Redox (reduction–oxidation, , ) is a type of chemical reaction in which the oxidation states of substrate (chemistry), substrate change. Oxidation is the loss of Electron, electrons or an increase in the oxidation state, while reduction is the gain of electrons or a decrease in the oxidation state. There are two classes of redox reactions: * ''Electron-transfer'' – Only one (usually) electron flows from the reducing agent to the oxidant. This type of redox reaction is often discussed in terms of redox couples and electrode potentials. * ''Atom transfer'' – An atom transfers from one 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 released by the iron. Although oxidation reactions are commonly associated with the formation of oxides, other chemical species can serve the same function. In hydrogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Realgar
Realgar ( ), also known as "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. 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 aluminium, magnesium and titani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iron
Iron () is a chemical element with symbol Fe (from la, ferrum) 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, right in front of oxygen (32.1% and 30.1%, respectively), forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. In its metallic state, iron is rare in the Earth's crust, limited mainly to deposition by meteorites. Iron ores, by contrast, are among the most abundant in the Earth's crust, although extracting usable metal from them requires kilns or furnaces capable of reaching or higher, about higher than that required to smelt copper. Humans started to master that process in Eurasia during the 2nd millennium BCE and the use of iron tools and weapons began to displace copper alloys, in some regions, only around 1200 BCE. That event is considered the transition from the Bronze Age to the Iron A ... [...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 smelte ... [...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 of copper in historic times and was used by pre-historic peoples. Native copper occurs rarely as isometric cubic and octahedral crystals, but more typically as irregular masses and fracture fillings. It has a reddish, orangish, and/or brownish color on fresh surfaces, but typically is weathered and coated with a green tarnish of copper(II) carbonate (also known as patina or verdigris). Its specific gravity is 8.9 and its 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 copper in the world. (Web archive; click cancel when it asks for authentication.) Native Americans mined ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smelting
Smelting is a process of applying heat to ore, to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal base behind. The reducing agent is commonly a fossil fuel source of carbon, such as coke—or, in earlier times, charcoal. The oxygen in the ore binds to carbon at high temperatures due to the lower potential energy of the bonds in carbon dioxide (). Smelting most prominently takes place in a blast furnace to produce pig iron, which is converted into steel. The carbon source acts as a chemical reactant to remove oxygen from the ore, yielding the purified metal element as a product. The carbon source is oxidized in two stages. First, the carbon (C) combusts with oxygen (O2) in the air to produce carbon monoxide (CO). Second, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
