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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Science / Faculty of Science >
Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy >
Vol.XXII, No.4 >
The Crystal Structure of Ramsdellite from Pirika Mine
| Title: | The Crystal Structure of Ramsdellite from Pirika Mine |
| Authors: | Miura, Hiroyuki Browse this author →KAKEN DB | | Kudou, Haruhiko Browse this author | | Choi, Jai Ho Browse this author | | Hariya, Yu Browse this author |
| Issue Date: | Aug-1990 |
| Publisher: | 北海道大学 |
| Journal Title: | 北海道大学理学部紀要 |
| Journal Title(alt): | Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy |
| Volume: | 22 |
| Issue: | 4 |
| Start Page: | 611 |
| End Page: | 617 |
| Abstract: | Chemical composition and crystal structure of ramsdellite from Pirika mine, Hokkaido, Japan were studied. Chemical composition, determined by EPMA, shows that ramsdellite is pure manganese oxide and does not contain any other element. The crystallographic data, obtained by Rietveld analysis, indicate that ramsdellite has orthorhombic symmetry. Space group is Pnma and unit cell parameters are: a=4.513(1)Å, b=9.264(1)Å and c=2.859(1)Å. The structure consists of MnO6 double chains (Byström, 1950). There are 4 symmetry-dependent MnO6 octahedral in an unit cell and 2 symmetry-independent oxygen atoms in an MnO6 octahedron. The difference of inter-atomic distances between Mn-O(1) and Mn-O(2) is larger than other manganese dioxide minerals. The distortion of MnO6 octahedron is quite similar to that of groutite (α-MnOOH). These data suggest that ramsdellite was formed by oxidation of groutite. |
| Type: | bulletin (article) |
| URI: | http://hdl.handle.net/2115/36769 |
| Appears in Collections: | Journal of the Faculty of Science, Hokkaido University. Series 4, Geology and mineralogy > Vol.XXII, No.4
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