Ramsbeckite from the Hirao mine at Minoo, Osaka, Japan

Accession number;04A0332440
Title;Ramsbeckite from the Hirao mine at Minoo, Osaka, Japan
Author;OHNISHI M(Kurashiki Univ. Sci. And The Arts, Kurashiki, Jpn)   KOBAYASHI S(Kurashiki Univ. Sci. And The Arts, Kurashiki, Jpn)   KUSACHI I(Okayama Univ., Okayama, Jpn)   YAMAKAWA J(Okayama Univ., Okayama, Jpn)   SHIRAKAMI M  
Journal Title;J Mineral Petrol Sci
Journal Code:G0150B
ISSN:1345-6296
VOL.99;NO.1;PAGE.19-24(2004)
Figure&Table&Reference;FIG.3, TBL.3, REF.9
Pub. Country;Japan
Language;English
Abstract;Ramsbeckite was found as a vein forming mineral in altered shale at the Hirao mine, Minoo, Osaka, Japan. It occurred as aggregates of euhedral granular crystals up to 0.5 mm across, in association with sphalerite, chalcopyrite, smithsonite, aurichalcite, amorphous manganese dioxide, schulenbergite, brochantite, serpierite, limonite and an unidentified mineral. It was emerald green to blue-green in color with a vitreous luster in hand specimen. An EPMA and CHNS/O analyzer gave the empirical formula (Cu9.380Zn5.542Ni0.034Co0.027Fe0.020Mn0.013).SIGMA.15.016[(SO4)3.871(CO3)0.166].SIGMA.4.037(OH)21.958 6.06H2O on the basis of O = 44. The unit cell parameters were a = 16.106 (3), b = 15.568 (2), c = 7.109 (1) .ANGS., .BETA. = 90.23 (1).DEG., and Z = 2. The mineral was optically biaxial negative with refractive indices .ALPHA. = 1.676, .BETA. = 1.704 and .GAMMA. = 1.707, and 2VX(calc) = 37.8.DEG.. The Vickers micro-hardness was 162 (144-182) kg/mm2 (10 g load), and the Mohs hardness was 3.5. The measured density was 3.36 g/cm3. It is likely that ramsbeckite at the Hirao mine crystallized from Cu and Zn-bearing fluids. (author abst.)
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