Explain the geochemistry and mineralogy of hydrothermal and magmatic tungsten deposits?
364418
Wow, what a question... This was the best I could come up with...\n\n"The characteristics of granitoid-related tungsten deposits hosted in siliceous (carbonate-free) rocks (e.g., Panasqueira, Cligga Head, Pasto Bueno) are reviewed and the ranges of physicochemical parameters of the ore-forming fluids are summarized. The two important tungsten minerals in these deposits are wolframite and scheelite, which were deposited mostly between 200° and 500°C and 200 and 1,500 bars. The salinities of the mineralizing fluids were typically less than 15 wt percent but commonly were significantly higher (up to 55 wt %). The two predominant dissolved components are Na+ and Cl– with subordinate Ca2+, K+, and carbonate species (/HCO3–). The contents of CO2 are highly variable, but XCO2 values typically range from 0 to 0.1. Limited pH and fO2 estimates indicate a moderately acidic fluid with oxygen fugacities between those of the QFM and HM buffers. These parameters were used to guide solubility and speciation modeling of W in hydrothermal fluids in granitoid environments."\n\nThanks for expanding my thinking!
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granite....sand...\nhttp://images.google.com/imgres?imgurl=http://library.thinkquest.org/05aug/00461/images/igneous.jpg&imgrefurl=http://library.thinkquest.org/05aug/00461/igneous.htm&h=423&w=640&sz=262&hl=en&start=17&tbnid=1_Wjmt6u5ghPyM:&tbnh=91&tbnw=137&prev=/images%3Fq%3Digneous%2Brocks%26svnum%3D10%26hl%3Den%26lr%3D\n\n\nthe most common....basalt...\nhttp://images.google.com/imgres?imgurl=http://www.learner.org/channel/courses/essential/earthspace/images/show5-brit-with-igneous.jpg&imgrefurl=http://www.learner.org/channel/courses/essential/earthspace/session3/closer.html&h=300&w=300&sz=28&hl=en&start=14&tbnid=iEnzTA6MoGvW4M:&tbnh=116&tbnw=116&prev=/images%3Fq%3Digneous%2Brocks%26svnum%3D10%26hl%3Den%26lr%3D\n\n\npumice...\nhttp://images.google.com/imgres?imgurl=http://www.otago.ac.nz/geology/features/rocks-minerals/pumice.jpg&imgrefurl=http://www.otago.ac.nz/geology/features/rocks-minerals/rocks.html&h=667&w=800&sz=47&hl=en&start=6&tbnid=QxNtL7z7RM7VCM:&tbnh=119&tbnw=143&prev=/images%3Fq%3Dpumice%26svnum%3D10%26hl%3Den%26lr%3D\n\nobsidian...\nhttp://images.google.com/imgres?imgurl=http://faculty.icc.edu/easc111lab/labs/labb/rocks/ibox.jpg&imgrefurl=http://faculty.icc.edu/easc111lab/labs/labb/igneous.html&h=330&w=265&sz=59&hl=en&start=47&tbnid=6qFg9tv5UzEBnM:&tbnh=119&tbnw=96&prev=/images%3Fq%3Digneous%2Brocks%26start%3D40%26ndsp%3D20%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN
546834
Native silver, that is to say pure silver, is very rare.  Most silver is locked up in other minerals.  Galena, the primary lead ore, looks something like silver, but has only 6-10% silver in it.  Silver is found in the sulfide enriched zones of copper mines, in tellurides, and many other ores.  Here's a few rockhound links,  just search Silver or Ag, and/or ores, and big pix will come up.\n\n\nhttp://www.mindat.org\nhttp://www.mining-technoloy.com/projects/index.html\nhttp://www.earthsci.org/teacher/bgasicgeol/resource.html  \n\nand of course the one site every one in earth science must know:\nhttp://www.rockhounds.com/rockshop/table.shtml\n\n\nThere are many tricks, but hardness isn't one of them.  Blowpipe analysis, which you can do, knowing the local geology, making friends with rockhounds, varous acid & base reactivies will all help.  Read eveything on these sites, and maybe a book or three on your area.
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It is a good site: http://minerals.er.usgs.gov/
258958
Hello,\n\n    The quotes below are taken from the Stillwater Mine web site. The deposit this mine uses in Montana is the largest palladium deposit in the world and unusual in that it contains much more palladium than platinum:\n\n"The platinum group metals (PGM) occur both in primary deposits and placers. The primary deposits are of two main types. The first consists of local concentrations of the metals in olivine-rich rocks, particularly in dunite. Often associated with chromite, native platinum or iridosmine is the principal constituent. The erosion of such deposits has been responsible for the formation of placer deposits of the platinum metals. The most important commercial dunite deposits are in the Ural Mountains of Russia and at the Overwacht in the Transvaal in South Africa. \n\nThe second type of primary deposit includes nickel-copper sulphide deposits that are generally associated with norite. These deposits, in which platinum and palladium predominate, make up the greatest known reserves of PGM metals. The most extensive deposits have been found in the norite belt of the Bushveld Igneous Complex in the Transvaal, the Stillwater Complex in Montana, USA, in the Sudbury district of Ontario Canada and the Norilsk Complex in Russia."\n\n    I hope that helps,\n\n    Steve
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crystallization from magma !!! like feldspar , quartz , olivine , pyroxene ...\n\nprecipitation from a solution !!! like calcite , halite , hematite, gypsum .. \n\nsome minerals form in the two ways .. like quartz which may crystallize from a magma as in granite or precipitate from Si rich solutions as in some sedimentary rocks when it fills the bores ..
204360
That was probably written by Aristotle or one of those fellows thousands of years ago.  The idea that minerals were formed by heavenly bodies was an idea that remained current up until about four or five hundred years ago.  This idea has its roots in alchemy and astrology and is why, if you look at astrological "theories", that each planet has an associated element.  Rays, or some sort of mysterious "emanation" from planets and stars were supposed to form deposits of minerals and metals in the earth, and this "theory" was even used to guide prospecting efforts for metals like gold, silver, iron, and whatnot.  Gold was associated with the sun, silver with the moon, iron with Mars, mercury with the planet Mercury, and so on.  \n\nObviously, this idea is a complete fantasy and has no real basis in science.
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woohoo geology... lets see if I remember anything...\n\nOkay here is a basic thing, the composition of rocks, especially it's silicate level, can tell us much about the molten/semimolten layers of Earth.... Okay I was enver very good in this subject, so look here...\nhttp://en.wikipedia.org/wiki/Geology
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Not much water in the form of free liquid water entrapped in pores of the rocks in subducted lithosphere that makes it into the mantle. However, the subducted plate *does* contain a substantial amount of water in the form of hydrous minerals  (e.g., clays, serpentine, amphiboles, chlorite, epidote, micas, etc.) that form by hydrothermal alteration of the oceanic crust, and are present in the overlying sediments (some of which are subducted).\n\nMuch of the water in these hydrous minerals is released when the subducted plate heats up as it is warmed by the hot mantle surrounding the plate, and the hydrous minerals dehydrate (really just a special type of prograde metamorphism).  The water that is released is thought to leave the plate itself and rise (because it is less dense than the rock, and hence bouyant) into the overlying mantle.  Water reduces the temperature at which  silicate rocks begin to melt, and because the mantle overlying the subducted slab is actually hotter than the slab itself, this water can trigger melting in the mantle.  This is why there is almost always a volcanic front above a subduction zone (e.g., the "Pacific ring of fire").  The magma associated with these subduction-zone volcanoes is usually volatile-rich (water and CO2 coming from hydrous minerals and carbonates in the subducted slab), and gives rise to explosive eruptions like Mt. St. Helens, or in a more extreme example, Krakatoa.
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ok. i am giving u links which will help u find the right information fast and efficiently. since you have to write in ur words, its better that u deduce the answers urself. it should be quite simple and it will help you.\n\nbasically granite is an igneous rock which is formed due to the cooling down and crystallization of molten magma. here are the links which will help u. there is a file included which is quite informative.\n\nMost of the sites have overlapping information, so use the info u need. Have fun and do cite the links as the sources
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+2.\n\n(The element is never found as a free element but does occur in the minerals columbite ((Fe,Mn)(Nb,Ta)2O6), columbite-tantalite or coltan ((Fe,Mn)(Ta,Nb)2O6), pyrochlore ((Na,Ca)2Nb2O6OH,F), and euxenite ((Y,Ca,Ce,U,Th)(Nb,Ta,Ti)2O6). )2 in subscript.
182621
Uranium is a naturally occurring element found at low levels in virtually all rock, soil, and water. It is considered to be more plentiful than antimony, beryllium, cadmium, gold, mercury, silver, or tungsten and is about as abundant as arsenic or molybdenum. It is found in many minerals including uraninite (most common uranium ore), autunite, uranophane, torbernite, and coffinite. Significant concentrations of uranium occur in some substances such as phosphate rock deposits, and minerals such as lignite, and monazite sands in uranium-rich ores (it is recovered commercially from these sources).\n\nThe decay of uranium, thorium and potassium-40 in the Earth's mantle is thought to be the main source of heat[5][6] that keeps the outer core liquid and drives mantle convection, which in turn drives plate tectonics.\n\nYou can find deposits of uranium by using a Geiger counter or by looking for other kinds of rock that uranium is found near.\n\nPlutonium, on the other hand, is not naturally occuring.  You can make plutonium by "enriching" uranium in special reactors.
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Check the link below.  It can be formed through volcanic activity as well as crystallizing out of mineral rich water deposits.  It is almost pure iron that is oxidized.
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You can extract it from Phosphate rock.\n\nLarge deposits are located in China, Russia, Morocco, Florida, Idaho, Tennessee, Utah, and elsewhere.
68904
coal, lignite, iron ore, copper, lead, zinc, uranium, tungsten, mercury, pyrites, magnesite, fluorspar, gypsum, sepiolite, kaolin, potash, hydropower, arable land
265420
Here, try this:\n\nhttp://www.rocks-and-minerals.com/\n\nCheers.
458863
You could start here:\n\nhttp://webmineral.com/data/Magadiite.shtml