Akimotoite, a new mineral discovered in a shocked meteorite
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- TOMIOKA Naotaka
- Kochi Institute for Core Sample Research, Japan Agency for Marine-Earth Science and Technology
Bibliographic Information
- Other Title
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- 衝撃変成を受けた隕石中に発見された新鉱物:秋本石
Abstract
<p>Akimotoite (IMA1997-044), (Mg,Fe)SiO3, a new silicate mineral of the ilmenite group, has been discovered in the shocked Tenham chondritic meteorite. It occurs as aggregates adjacent to clinoenstatite in host-rock fragments trapped into shock-induced melt veins. Chemical analysis gives the simplified formula to be (Mg0.79Fe0.21)SiO3, the same as for clinoenstatite. Selected-area electron diffraction (SAED) patterns correspond to the synthetic (Mg,Fe)SiO3 ilmenite phase with the space group R3. The lattice parameters estimated from the SAED patterns are a = 0.478(5) nm, c = 1.36(1) nm in the hexagonal setting. The calculated density is 4.0(1) g/cm3. In a shock-induced melt vein, akimotoite and clinoenstatite are intergrown with a topotaxial relationship in which close-packed oxygen layers of both phases are preserved. This occurrence suggests that the enstatite-akimotoite transition was caused by a shear transformation mechanism without long-range atomic diffusion.</p>
Journal
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- Japanese Magazine of Mineralogical and Petrological Sciences
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Japanese Magazine of Mineralogical and Petrological Sciences 53 (1), n/a-, 2024
Japan Association of Mineralogical Sciences
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Details 詳細情報について
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- CRID
- 1390580143068236672
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- ISSN
- 13497979
- 1345630X
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- Text Lang
- ja
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- Data Source
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- JaLC
- Crossref
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- Abstract License Flag
- Disallowed