- Jarosite
Jarosite is a basic hydrous
sulfate ofpotassium andiron with a chemical formula of KFe(III)3(OH)6(SO4)2. Thismineral is formed inore deposits by theoxidation of ironsulfide s. Jarosite is often produced as a byproduct during the purification and refining ofZinc and is also commonly associated with AMD (acid mine drainage ) environments.Physical Properties
Jarosite is hexagonal and brittle, with basal cleavage, a hardness of 2.5-3.5, and a
specific gravity of 3.15-3.26. It is translucent to opaque with a vitreous to dull lustre, and is coloured dark yellow to yellowish-brown. It can sometimes be confused withlimonite orgoethite with which it commonly occurs in thegossan (oxidized cap over an ore body). Jarosite is an iron analogue of the potassium aluminium sulfate,alunite .History
Jarosite was first described in 1852 by
August Breithaupt in the Barranco del Jaroso in the Sierra Almagrera (near Los Lobos, Cuevas del Almanzora, Almería,Spain ).In 2004 Jarosite was detected on Mars by a
Mössbauer spectrometer on theMER-B rover, which has been interpreted as strong evidence that Mars once possessed large amounts of liquid water.Use in materials science
Jarosite is also a more generic term denoting an extensive family of compounds of the form AM3(OH)6(SO4)2, where A+ = Na, K, Rb, NH4, H3O, Ag, Tl and M3+ = Fe, Cr, V. In
condensed matter physics andmaterials science they are renowned for containing layers withkagome lattice structure, relating togeometrically frustrated magnet s [cite journal | last = Harrison | first = A. | year = 2004 | title = First catch your hare: the design and synthesis of frustrated magnets | journal = J. Phys.: Condens. Matter | volume = 16 | issue = 9-12 | pages = S553–S572 | doi = 10.1088/0953-8984/16/11/001 ] , [cite journal | last = Wills | first = A. S. et al. | year = 2000 | title = Magnetic properties of pure and diamagnetically doped jarosites: Model kagomé antiferromagnets with variable coverage of the magnetic lattice | journal = Phys. Rev. B | volume = 61 | issue = 9 | pages = 6156–6169 | doi = 10.1103/PhysRevB.61.6156] .References
* Palache, C., H. Berman, and C. Frondel (1951) Dana’s system of mineralogy, (7th edition), v. II, 560–562
* [http://www.mindat.org/min-2078.html Mindat]
* [http://webmineral.com/data/Jarosite.shtml Webmineral data]
* [http://rruff.geo.arizona.edu/doclib/hom/jarosite.pdf Mineral Data PDF]
* [http://www.news.cornell.edu/Chronicle/04/3.4.04/jarosite.html Cornell University (2004) "How an obscure mineral provided a vital clue to Martian water"]External links
* [http://tierra.rediris.es/jarosite/ Further information about the Jaros Hydrothermal system]
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