低対称性の興安石類縁鉱物

宮脇 律郎; 門馬 綱一; 松原 聰; 重岡 昌子; 岡本 鑑吉; クリスチャンセン ロイ

doi:10.14824/jakoka.2016.0_47

2016 Annual Meeting of Japan Association of Mineralogical Sciences

Session ID : R1-11

DOI https://doi.org/10.14824/jakoka.2016.0_47

Conference information

Host: Japan Association of Mineralogical Sciences

R1: Characterization and description of minerals

Symmetry lowering in some hingganite related minerals

*Ritsuro Miyawaki, Koichi Momma, Satoshi Matsubara, Masako Shigeoka, Akiyoshi Okamoto, Roy Kristiansen

Author information

Keywords: hingganite, gadolinite, datolite, crystal structure, ordering

CONFERENCE PROCEEDINGS FREE ACCESS

Details

Abstract

A B-bearing hingganite related mineral shows an ordering of (Y,Yb)/(Y,Ca) at the 8-coordinated Y-sites to lower the symmetry of monoclinic crystal structure from P2₁/a to P2₁. This mineral, [(Y,Yb)(Y,Ca)]( ,Fe)Si₂₍Be,B)₂O₈(OH)₂, is characterized with a solid solution towards datolite composition [Ca₂ Si₂B₂O₈(OH)₂] in addition to the other end member composition [YCa _⅔Fe³⁺_⅓Si₂Be₂O₈(OH)₂].

Corresponding author

Register with J-STAGE for free!