Arakiite (IMA symbol: Ark) is a rare mineral with the formula (Zn,Mn2+)(Mn2+,Mg)12(Fe3+,Al)2(As3+O3)(As5+O4)2(OH)23.Roberts, A.C., Grice, J.D., Cooper, M.A., Hawthorne, F.C., and Feinglos, M.N., 2000. A new Zn-bearing hematolite-like mineral from Långban, Värmland, Sweden. Mineralogical Record 31(3), 253-256 It is both arsenate and arsenite mineral, a combination that is rare in the world of minerals. Arakiite is stoichiometrically similar to hematolite. It is one of many rare minerals coming from the famous Långban manganese skarn deposit in Sweden. Other minerals bearing both arsenite and zinc include kraisslite and mcgovernite.
The mineral crystallizes in the monoclinic crystal system in space group Cc.
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