@article{oai:tohoku.repo.nii.ac.jp:00050223, author = {南部, 松夫 and 岡田, 広吉 and 谷田, 勝俊 and 五十嵐, 俊雄}, issue = {2}, journal = {東北大學選鑛製錬研究所彙報 = Bulletin of the Research Institute of Mineral Dressing and Metallurgy, Tohoku University}, month = {Mar}, note = {application/pdf, The limonite and manganese oxide ores deposited from recent mineral springs at Arikurazawa occur on rhyolite of miocene age in layer form. The lower part of the ore bodies are composed of manganese oxide, and though the upper part of limonite ore. From the texture and structure of the ores, the former is considered to be precipitated chiefly by chemical action, while the latter is biochemically. The limonite is amorphous in X-ray examination, but it is considered from its dehydration phenomena as aggregate of very fine crystallites of hydrated ferric oxides. Though manganese oxide mineral is identified as mineral birnessite, the phase change by heating is rather similar to artificial δ-MnO_2. This specimen is considerably pure, but the result calculated on Jones and Milne's formula from its chemical composition does not show desirable agreement. Therefore, chemical formula of this mineral will have to be reconsidered., 紀要類(bulletin), 830858 bytes}, pages = {159--168}, title = {<報文>福島県沼沢沼附近有倉沢の褐鉄鉱と酸化マンガン鉱について}, volume = {18}, year = {1963} }