著者

佐藤 トゥイウェン 清水 政明 近藤 美佳 サトウ トゥイウェン シミズ マサアキ コンドウ ミカ Sato Thuy Uyen Shimizu Masaaki Kondo Mika

出版者

大阪大学世界言語研究センター

雑誌

大阪大学世界言語研究センター論集 (ISSN:18835139)

巻号頁・発行日

vol.7, pp.263-283, 2012-03-08

著者

MATSUBARA Satoshi MIYAWAKI Ritsuro YOKOYAMA Kazumi SHIMIZU Masaaki IMAI Hiroyuki

出版者

日本鉱物科学会

雑誌

Journal of mineralogical and petrological sciences (ISSN:13456296)

巻号頁・発行日

vol.99, no.6, pp.363-367, 2004-12-01

被引用文献数

2 9

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Tokyoite, Ba₂Mn³⁺(VO₄)₂(OH), the Mn³⁺-analogue of gamagarite, is found from the Shiromaru mine, Okutama, Tokyo, Japan. It is monoclinic, <i>P</i>2₁/<i>m</i>, <i>a</i> = 9.10(4), <i>b</i> = 6.13(2), <i>c</i> = 7.89(5) Å, β = 112.2(5)°, Z = 2. The strongest lines in the powder X-ray diffraction pattern are 3.73 (15) (111), 3.31 (100) (112), 3.08 (20) (020), 3.00 (16) (301, 212, 102), 2.90 (19) (120), 2.80 (62) (121, 300), 2.16 (18) (321), 1.963 (15) (204). Electron microprobe analysis gave V₂O₅ 31.77, SiO₂ 0.15, Al₂O₃ 0.07, Fe₂O₃ 2.33, Mn₂O₃ 11.27, CaO 0.07, BaO 51.91, SrO 0.22, Na₂O 0.13, H₂O (calc.) 1.59, total 99.51 wt. %, and lead to the empirical formula, (Ba_1.92Na_0.02Sr_0.01Ca_0.01)_Σ1.96(Mn³⁺_0.81Fe³⁺_0.17Al_0.01)_Σ0.99[(V_1.99Si_0.01)O_7.92](OH)_1.00 on the basis of V + Si = 2 and (OH) = 1. It is translucent and black red in color with a vitreous luster. The streak is dark brownish red and cleavage is not observed. The Mohs' hardness is about 4 to 4.5. The calculated density is 4.62 g/cm³. It has distinct pleochroism, from reddish orange to dark brownish red in thin section and the calculated mean refractive index is 2.03. It occurs as irregular grains under 15 μm, and the aggregates are up to 250 μ</i>m wide in association with braunite, hyalophane and tamaite. The mineral is formed under the later stage activity of low grade metamorphism.

著者

HORI Hidemichi KOBAYASHI Toshinori MIYAWAKI Ritsuro MATSUBARA Satoshi YOKOYAMA Kazumi SHIMIZU Masaaki

出版者

日本鉱物科学会

雑誌

Journal of mineralogical and petrological sciences (ISSN:13456296)

巻号頁・発行日

vol.101, no.4, pp.170-177, 2006-08-01

被引用文献数

1 8

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Iwashiroite-(Y), YTaO₄, was found from Suishoyama, Kawamata Town, Fukushima Prefecture, Japan. It is monoclinic</i>, <i>P</i>2/<i>a</i>, <i>a</i> = 5.262(5) Å, <i>b</i> = 5.451(5) Å, <i>c</i> = 5.110(5) Å, β = 95.12(10)°, <i>V</i> = 146.0(2) ų, Z = 2. The five strongest lines in the powder XRD pattern [<i>d</i>(Å), <i>I</i>/<i>I</i>₀, <i>hkl</i>] are (3.13, 100, 111), (2.95, 94, 111), (2.73, 26, 020), (1.890, 29, 220) and (1.862, 29, 022). Electron microprobe analysis gave; Y₂O₃ 29.10, Ce₂O₃ 0.10, Nd₂O₃ 0.10, Sm₂O₃ 0.36, Gd₂O₃ 1.06, Tb₂O₃ 0.25, Dy₂O₃ 2.38, Ho₂O₃ 0.56, Er₂O₃ 2.09, Tm₂O₃ 0.37, Yb₂O₃ 3.33, Lu₂O₃ 0.85, ThO₂ 0.02, UO₂ 0.15, CaO 0.17, Ta₂O₅ 40.64, Nb₂O₅ 16.66, TiO₂ 0.41, total 98.60 wt%, and leads to the empirical formula, (Y_0.81Yb_0.05Dy_0.04Er_0.03</sub>Gd_0.02Lu_0.01Ho_0.01Sm_0.01Ca_0.01Tm_0.01)_Σ1.00(Ta_0.58Nb_0.39T_i0.02)_Σ0.99O₄ on the basis of the 4 oxygen atoms per formula unit. Iwashiroite-(Y) is translucent and amber brown to brown in color with a glassy to subadamantine luster. The streak is pale brown and cleavage is {010} good, {001} poor. The Mohs' hardness is 6. The calculated density is 7.1 g/cm³. Iwashiroite-(Y) occurs as an aggregate of small euhedral platy crystals with a metamict substance in the main ore body of the granite pegmatite mine at the locality. Associated minerals are quartz, microcline and annite. The crystal structure was refined to <i>R</i> = 0.034 with single crystal XRD data. Although the structure consists of TaO₆ octahedra and YO₈ polyhedra, iwashiroite-(Y) is not isostructural with fergusonite-beta-(Y).