Chalcanthite 565010 225798603 2008-07-15T13:27:32Z MushiHoshiIshi 5498721 [[ja:胆礬]] {{Infobox mineral | name = Chalcanthite | category = | boxwidth = | boxbgcolor = | image = Chalcanthite.jpg | caption = | formula = [[Copper|Cu]]{{sulfate}}{{hydrate|5}} <br> ([[copper(II) sulfate|copper(II) sulfate pentahydrate]]) | molweight = | color = Blue; Green | habit = typically stalactitic, encrusted, reniform or massive. Natural crystals are rare, but are short prismatic or tabular | system = Triclinic | twinning = | cleavage = [110] Imperfect, Indistinct; [111] Indistinct | fracture = Conchoidal | mohs = 2.5 | luster = Vitreous | refractive = | opticalprop = | birefringence = | pleochroism = None | streak = White | gravity = 2.12 - 2.3 | melt = | fusibility = | diagnostic = | solubility = Soluble in water, turning it blue | diaphaneity = Transparent to translucent | other = [[Image:Hazard T.svg|30px]] [[Poisonous]] }} '''Chalcanthite''', whose name derives from the Greek, ''chalkos'' and ''anthos'', meaning copper flower, is a richly-colored blue/green [[solvent|water-soluble]] [[sulfate]] [[mineral]], commonly found in the late-stage oxidation zones of [[copper]] deposits. Due to its ready solubility, chalcanthite is more frequently found in greater abundance in arid regions. Chalcantite is the most common member of a group of related hydrated sulfates. These other sulfates are identical in chemical composition to chalcanthite, with the exception of replacement of the copper [[ion]] by either [[manganese]] (forming [[jokokuite]], [[Manganese|Mn]]{{sulfate}}{{hydrate|5}}, [[iron]] (forming [[siderotil]], [[Iron|Fe]]{{sulfate}}{{hydrate|5}}), or [[magnesium]] (forming [[pentahydrite]], [[Magnesium|Mg]]{{sulfate}}{{hydrate|5}}). == Uses of chalcanthite == As chalcanthite is a copper mineral, it can be used as an [[ore]] of copper. However, its ready solubility in [[water]] means that it tends to crystallize, dissolve, and recrystallize as crusts over any mine surface in more humid regions. Therefore, chalcanthite is only found in the most arid regions in sufficiently large quantities for use as an ore. Secondarily, chalcanthite, due to its rich color and beautiful [[crystal]]s, is a sought after collector's mineral. However, as with its viability as an ore, the solubility of the mineral causes significant problems. First, the mineral readily absorbs and releases its water content, which, over time, leads to a disintegration of the crystal structure, destroying even the finest specimens. Second, higher quality crystals can be easily grown synthetically, and, as such, there is a concern that disreputable mineral dealers would present a sample as natural when it is not. == Associated minerals == Given that chalcanthite is found in oxidized copper deposits, it is frequently found in association with other copper minerals. Frequently associated minerals include * [[Calcite]] and its [[allotropy|polymorph]], [[aragonite]], both [[calcium|Ca]]{{carbonate}} * [[Brochantite]], [[copper|Cu]]<sub>4</sub>({{sulfate}})({{hydroxide}})<sub>6</sub> * [[Chalcopyrite]], [[copper|Cu]][[Iron|Fe]][[sulfur|S]]<sub>2</sub> * [[Malachite]], [[copper|Cu]]<sub>2</sub>({{carbonate}})({{hydroxide}})<sub>2</sub> * [[Melanterite]], [[iron|Fe]]{{sulfate}}{{hydrate|7}} == Alternative names == Chalcanthite has several alternative names, including ''[[blue stone]]'', ''blue vitriol'', and ''copper vitriol''. == Notes for identification == Chalcanthite's blue color is one of its most notable features, but it is insufficient in identification. Other useful tests include associated minerals, [[crystal habit]], solubility and subsequent coloring of the water blue, and taste. A special note on tasting chalcanthite, however: chalcanthite has a sweetly metallic taste, but taste testing should not be done haphazardly. The specimen should be lightly touched to the tip of the tongue only, as chalcanthite is '''poisonous'''. ==See also== *[[Copper(II) sulfate]] == References == * [http://webmineral.com/data/Chalcanthite.shtml WebMineral Listing] * [http://www.mindat.org/min-959.html MinDat Listing] * [http://mineral.galleries.com/minerals/sulfates/chalcant/chalcant.htm Mineral Galleries] [[Category:Hydrates]] [[Category:Copper minerals]] [[Category:Sulfate minerals]] [[ca:Calcantita]] [[cs:Chalkantit]] [[de:Chalkanthit]] [[es:Chalcantita]] [[eu:Kalkantita]] [[fr:Chalcantite]] [[gl:Calcantita]] [[it:Calcantite]] [[ja:胆礬]] [[hu:Kalkantit]] [[nl:Chalcanthiet]] [[pl:Chalkantyt]] [[pt:Calcantite]] [[ru:Халькантит]] [[sk:Chalkantit]] [[uk:Халькантит]]