Metatorbernite 4079732 216240313 2008-05-31T19:22:52Z Pere prlpz 2176094 [[ca:Meta-torbernita]] {{Infobox mineral | name = Metatorbernite | category = | boxwidth = | boxbgcolor = | image = Metatorbernite.jpg | caption = Green platy crystals on [[granite]] | formula = [[Copper|Cu]]([[Uranium|U]][[Oxygen|O]]<sub>2</sub>)<sub>2</sub><!-- -->([[Phosphorus|P]][[Oxygen|O]]<sub>4</sub>)<sub>2</sub>ยท<!-- -->8([[Hydrogen|H]]<sub>2</sub>[[Oxygen|O]]) | molweight = | color = Light to dark green | habit = Flat plates | system = [[Tetragonal]]-dipyramidal | twinning = | cleavage = Perfect | fracture = Brittle | mohs = 2.5 | luster = Vitreous, adamantine | refractive = 1.624-1.626 | opticalprop = | birefringence = | pleochroism = | streak = Light green | gravity = 3.7-3.8 | melt = | fusibility = | diagnostic = | solubility = | diaphaneity = | other = [[Image:Radioactive.svg|25px]] [[Radioactive]] }} '''Metatorbernite''' (or '''meta-torbernite''') is a [[radioactive decay|radioactive]] [[phosphate minerals|phosphate mineral]], and is a [[dehydration]] [[pseudomorph]] of [[torbernite]]. Chemically, it is a [[copper]] [[uranyl]] [[phosphate]] and usually occurs in the form of green platy deposits. It can form by direct deposition from a [[supersaturation|supersaturated]] solution, which produces true crystalline metatorbernite, with a dark green colour, translucent [[diaphaneity]], and vitreous lustre. However, more commonly, it is formed by the dehydration of torbernite, which causes internal stress and breakage within the [[crystal structure|crystal lattice]], resulting in crystals composed of microscopic powder held together using [[Electrostatics|electrostatic]] force, and having a lighter green colour, opaque diaphaneity, and a relatively dull lustre. As with torbernite, it is named after the [[Sweden|Swedish]] [[chemist]] [[Tornbern Bergmann]]. It is especially closely associated with torbernite, but is also found amongside [[autunite]], [[meta-autunite]] and [[uraninite]]. [[Image:Metatorbernite with autunite.jpg|left|thumb|200px|Green metatorbernite with yellow autunite deposits on granite]] ==References== *[http://www.mindat.org/min-2689.html MinDAT] *[http://webmineral.com/data/Metatorbernite.shtml Webmineral] *[http://www.uraniumminerals.com/UTh/M-Torbernite.htm Uranium minerals] <div style="clear: both"></div> {{mineral-stub}} [[Category:Uranium minerals]][[Category:Copper minerals]][[Category:Phosphate minerals]] [[ca:Meta-torbernita]] [[it:Metatorbernite]] [[hu:Metatorbernit]]