| 概要 |
Brownish green minerals occur in amigdales of altered andesite agglomerate from Tsuyazaki formation (Miocene), Tsuyazaki-machi, Fukuoka Prefecture, Japan. Chemical composition: SiO_2 39.12, TiO_2 0.99..., Al_2O_3 12.84, Fe_2O_3 9.98, FeO 0.19, MnO 0.23, MgO 12.86, CaO 1.50, Na_O 2.55, K_2O 0.34, P_2O_5 0.19 H_2O+ and H_2O- 19.38, total 100.17_7％. The material is chemically similar to cardinite, i.e. the weathering product from biotite described by MacEwan (1948). The structural formula is: (Ca_0.26Na_0.79K_0.07) (Al_0.79Fe^3+_1.22Fe^2+_0.05Mg_3.10) (Si_6.34Al_1.66) O_20(OH)_10・nH_2O. The visual inspection of x-ray diffraction paterns before and after various treatments shows that this mineral is a randomly interstratified mineral of vermiculite and saponite. This mineral is considered to be formed from an illite mineral (ceradonite) in amigdales by weathering. D. T. A. and I. R. data are also described.続きを見る
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Mendeley出力
