The derivative structure of silicate garnets in grandite

Takéuchi, Yoshio; Haga, Nobuhiko; Umizu, Shigetomo; Satô, Gen P.

doi:10.1524/zkri.1982.0005

Cited by 32 publications

(61 citation statements)

References 10 publications

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“…The extinction rule for the body-centered lattice (hkl: h + k + l = 2n) was applied for the data collection. For the convenience of comparison with previous studies (e.g., Takéuchi et al, 1982;Kingma and Downs, 1989), the space group setting I 1 was selected although it was irregular setting for the triclinic symmetry. The SC-XRD experiment was also performed using synchrotron radiation at the beam line BL-10A, Photon Factory, KEK, Japan to check the space group.…”

Section: Single-crystal X-ray Diffraction Experimentsmentioning

confidence: 99%

“…The fractional atom coordinates of a I 1 model reported by Takéuchi et al (1982) were applied as initial structure models. The atomic scattering factors for all atoms were obtained from the International Tables for Crystallography, vol.…”

Section: Single-crystal X-ray Diffraction Experimentsmentioning

confidence: 99%

“…The crystal structures of birefringent ugrandite were reported as orthorhombic structure with the space group Fddd or triclinic structure with the space group I 1 (e.g. Takéuchi et al, 1982;Allen and Buseck, 1988;Wildner and Andrut, 2001;Frank-Kamenetskaya et al, 2007;Kobayashi et al, 2013;Nakamura et al, 2016). Kingma and Downs (1989) examined the crystal structure of iridescent andradite from a skarn deposit in the Sonoma Range, Nevada, USA.…”

Section: Introductionmentioning

confidence: 99%

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Cation ordering in iridescent garnet from Tenkawa village, Nara prefecture, Japan

Nakamura

Kuribayashi

Nagase

et al. 2017

Journal of Mineralogical and Petrological Sciences

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The crystal structure of iridescent garnet from Tenkawa village, Nara prefecture, Japan was investigated by means of Single-crystal X-ray diffraction method. The garnet crystal is composed of {110} c and {211} c growth sectors and shows birefringence under the crossed polarizer. The BSE image of the cross section shows very fine lamellae texture consisting of andradite-rich and grossular-rich layers. The average chemical composition was determined as Ca 3.01 (Fe 1.93 Al 0.09 ) Σ2.02 Si 2.99 O 12 . The unit-cell parameters were obtained as follows; a = 12.0540(17), b = 12.0580(13), c = 12.0612(13) Å, α = 89.986(9), β = 89.994(10) and γ = 89.994 (10)°. Some reflections which violate the extinction rule for the space group Ia 3d were observed and indicated that all glide planes are absent. Triclinic symmetry with the space group I 1 should be suitable for the structure refinement. The refinement with a I 1 model was convergent with R1 = 3.19%. The Fe 3+ occupancies of the Y11, Y12, Y13, Y14, Y 21, Y22, Y 23, and Y 24 were determined as 86.9(6), 96.1(6), 90.9(6), 98.0(6), 95.1(6), 91.3(6), 93.7(6), and 99.6(6)%, respectively. The Fe 3+ occupancy of the Y11 site is relatively lower, and that of the Y 24 site is higher. The iridescent garnet from Tenkawa shows very fine lamellae texture consisted of Fe-rich and Al-rich layers, therefore, the refined crystal structure of the Tenkawa garnet should be a superimposed structure of these chemically distinct layers. The Fe-rich layer have almost pure andradite composition, so cation ordering in the Fe-rich layer is negligible. The Al-rich layer should have more obvious ordered cation distribution than the Ferich layer. The ordered cation distribution in the Al-rich layer should mainly contribute the cation ordering in the refined crystal structure of the Tenkawa garnet.

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Section: Single-crystal X-ray Diffraction Experimentsmentioning

confidence: 99%

Section: Single-crystal X-ray Diffraction Experimentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Cation ordering in iridescent garnet from Tenkawa village, Nara prefecture, Japan

Nakamura

Kuribayashi

Nagase

et al. 2017

Journal of Mineralogical and Petrological Sciences

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“…Some mechanisms of ordering have been reported as the origin of the optical anisotropy in garnets; 1) ordering undetected rare earth elements substituting for Ca in the dodecahedral site (Blanc and Maisonneuve, 1973;Gaspar et al, 2008), 2) non -cubic distribution of OH groups due to the hydrogarnet constituent, in which [SiO 4 ] is substituted by [(OH) 4 ] (Rossman and Aines, 1986), 3) partial ordering of Ca 2+ and Fe 2+ in the distorted dodecahedral sites and/or Fe 3+ and Al 3+ in the octahedral sites (Takéuchi et al, 1982;Akizuki, 1984;Allen and Buseck, 1988). Hofmeister et al (1998) also proposed that the mismatch in size between Ca 2+ and Mg 2+ exacerbates retention of residual strain from study of forty anisotropic single -crystal garnets of quaternary system of pyralspite -grossular.…”

Section: Introductionmentioning

confidence: 99%

“…In the grossular -andradite solid solution series, optically anisotropic members have been known, and the refinements of their crystal structures (Takéuchi et al, 1982;Allen and Buseck, 1988;Kingma and Downs, 1989) have shown that they crystallize in orthorhombic (Fddd) or triclinic (I1 _ ). The origin of the birefringence has been a matter of some debate.…”

Section: Introductionmentioning

confidence: 99%

Anisotropic garnet from the Yamansu ore deposit, Xinjiang, China

Kobayashi

Miyawaki

Momma

et al. 2013

Journal of Mineralogical and Petrological Sciences

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Adsorption and co‐precipitation reactions at the mineral‐fluid interface: natural and anthropogenic processes

Wogelius

2013

Crystal Research and Technology

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The processes of adsorption and co‐precipitation at mineral surfaces during reactions with aqueous fluids play a critical role in controlling the mass transfer and bioavailability of nutrients and contaminants. Significant advances have been made in our understanding of these two processes through the application of synchrotron‐based analytical techniques including X‐ray Absorption Spectroscopy (XAS), X‐ray surface scattering methods, X‐ray fluorescence, and glancing incidence diffraction. Along with these methodologies, a wide range of other techniques involving infra‐red spectroscopy, atomic‐force microscopy, electron and particle beams have also contributed to understanding atomic‐scale processes at mineral surfaces. Here, the basics of each of these synchrotron methods are introduced along with an illustrative example from the literature. The allied techniques are also discussed. After this introduction, two case studies dealing with major contemporary environmental problems that involve adsorption and co‐precipitation are presented. The first concerns the mobility of arsenic in groundwater. Currently, dissolved arsenic species pose an environmental threat to millions of people. The second case study considers the speciation and uptake of uranium within UK radioactive waste sludge. Clean‐up of these sludges is expected to be a challenging technological problem, and the insights provided through understanding the attachment of the uranium to the sludge minerals may be critical to devising a successful remediation strategy.

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The derivative structure of silicate garnets in grandite

Cited by 32 publications

References 10 publications

Cation ordering in iridescent garnet from Tenkawa village, Nara prefecture, Japan

Cation ordering in iridescent garnet from Tenkawa village, Nara prefecture, Japan

Anisotropic garnet from the Yamansu ore deposit, Xinjiang, China

Adsorption and co‐precipitation reactions at the mineral‐fluid interface: natural and anthropogenic processes

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