TY - JOUR
T1 - Bosoite, a new silica clathrate mineral from Chiba Prefecture, Japan
AU - Momma, Koichi
AU - Ikeda, Takuji
AU - Nagase, Toshiro
AU - Kuribayashi, Takahiro
AU - Honma, Chibune
AU - Nishikubo, Katsumi
AU - Takahashi, Naoki
AU - Takada, Masayuki
AU - Matsushita, Yoshitaka
AU - Miyawaki, Ritsuro
AU - Matsubara, Satoshi
N1 - Funding Information:
We are grateful to Drs Masahiko Tanaka and Yoshio Katsuya for their support at BL15XU SPring-8 (Proposal No. 2007A4503) and Mr. Taiji Oyama of JASCO for his arrangement on Raman spectroscopy measurement at JASCO Laboratory. The authors also thank Dr Stuart Mills, Principal Editor and two anonymous reviewers for critical comments and suggestions. The preliminary SXRD data was obtained by KEK photon factory BL10A (PAC. No. 2012G112, 2014G173). This study was supported partially by JSPS KAKENHI Grant Numbers JP24740359 and JP16H05742.
Publisher Copyright:
Copyright © The Author(s), 2020. Published by Cambridge University Press on behalf of The Mineralogical Society of Great Britain and Ireland.
PY - 2020/12
Y1 - 2020/12
N2 - Bosoite (IMA2014-023) is a new silica clathrate mineral containing hydrocarbon molecules in its crystal structure. Bosoite can be considered structurally as a silica analogue of the structure-H gas hydrate, where guest molecules are trapped in cage-like voids constructed of the host framework. The mineral occurs in the Miocene tuffaceous sedimentary rocks at Arakawa, Minami-boso City, Chiba Prefecture, Japan. Bosoite is hexagonal, and it crystallises as an epitaxial intergrowth on chibaite crystals, with the {0001} of bosoite parallel to octahedral {111} form of chibaite. Crystals are colourless and transparent with vitreous lustre. The calculated density is 2.04 g/cm3. The empirical formula (based on 2 O apfu and guest molecules assumed as CH4) is Na0.01(Si0.98Al0.02)Σ1.00O2?0.50CH4; the end-member formula is SiO2?nCxH2x+2. Bosoite has the space group P6/mmm, with the unit-cell parameters a = 13.9020(3) Å, c = 11.2802(2) Å, V = 1887.99(6) Åand Z = 34. The crystal structure of bosoite was refined by single-crystal X-ray diffraction and converged to R1 = 4.26% for the average model and R1 = 2.96% for the model where all oxygen sites are split.
AB - Bosoite (IMA2014-023) is a new silica clathrate mineral containing hydrocarbon molecules in its crystal structure. Bosoite can be considered structurally as a silica analogue of the structure-H gas hydrate, where guest molecules are trapped in cage-like voids constructed of the host framework. The mineral occurs in the Miocene tuffaceous sedimentary rocks at Arakawa, Minami-boso City, Chiba Prefecture, Japan. Bosoite is hexagonal, and it crystallises as an epitaxial intergrowth on chibaite crystals, with the {0001} of bosoite parallel to octahedral {111} form of chibaite. Crystals are colourless and transparent with vitreous lustre. The calculated density is 2.04 g/cm3. The empirical formula (based on 2 O apfu and guest molecules assumed as CH4) is Na0.01(Si0.98Al0.02)Σ1.00O2?0.50CH4; the end-member formula is SiO2?nCxH2x+2. Bosoite has the space group P6/mmm, with the unit-cell parameters a = 13.9020(3) Å, c = 11.2802(2) Å, V = 1887.99(6) Åand Z = 34. The crystal structure of bosoite was refined by single-crystal X-ray diffraction and converged to R1 = 4.26% for the average model and R1 = 2.96% for the model where all oxygen sites are split.
KW - Japan
KW - bosoite
KW - chibaite
KW - hydrocarbon
KW - new mineral
KW - silica clathrate
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U2 - 10.1180/mgm.2020.91
DO - 10.1180/mgm.2020.91
M3 - Article
AN - SCOPUS:85099390743
VL - 84
SP - 941
EP - 948
JO - Mineralogical Magazine
JF - Mineralogical Magazine
SN - 0026-461X
IS - 6
ER -