Iyoite, MnCuCl(OH)3 and misakiite, Cu3Mn(OH)6Cl2: new members of the atacamite family from Sadamisaki Peninsula, Ehime Prefecture, Japan. (2nd January 2018)

• Record Type: Journal Article
• Authors: Nishio–hamane, D.; Momma, K.; Ohnishi, M.; Shimobayashi, N.; Miyawaki, R.; Tomita, N.; Okuma, R.; Kampf, A. R.; Minakawa, T.
• Is Part Of: Mineralogical magazine. Volume 81:Number 3(2017)
• Page Start: 485
• Page End: 498
• Publication Date: 2018-01-02
• Subjects: iyoite, -- misakiite, -- Mn-Cu ordering, -- atacamite family, -- new minerals, -- crystal structures, -- mineral synthesis, -- Sadamisaki Peninsula, -- Ehime Prefecture, -- Japan; Mineralogy -- Periodicals; Mineralogy -- Great Britain -- Periodicals; 549.05
• DOI: 10.1180/minmag.2016.080.104
• Languages: English
• ISSNs: 0026-461X

Abstract

Abstract: Two new members of the atacamite family were discovered recently in the Sadamisaki Peninsula, Ehime Prefecture, Japan. Iyoite, MnCuCl(OH)3, is an Mn-Cu ordered analogue of botallackite, while misakiite, Cu3 Mn(OH)6 Cl2, is an Mn-rich analogueof kapellasite. Both minerals occur in manganese ore crevices in close association with one another. Iyoite forms radial and dendritic aggregates consisting of pale green, bladed crystals. Misakiite commonly exists in emerald green, tabular, hexagonal crystals. The densities of iyoite andmisakiite were calculated to be 3.22 and 3.42 g cm –3 based on their empirical formulae and powder X-ray diffraction data. Under the same axial setting of botallackite, iyoite is monoclinic, space group P 21 / m, a = 5.717(2), b = 6.586(2), c = 5.623(3) Å, β = 88.45(3)° and V = 211.63(15) Å 3 . Misakiite is trigonal, space group P 3 m 1, with a = 6.4156(4), c = 5.7026(5) Å and V = 203.27(3) Å 3 . The structures of both mineralsare classified as layer type and the two are closely related. These new minerals were formed by the reaction between seawater and naturally-occurring manganese ores including native copper. These minerals are challenging to produce synthetically. Misakiite was synthesized successfully usinga hydrothermal method, while iyoite could not be made.