Details
| Original language | English |
|---|---|
| Pages (from-to) | 640-646 |
| Number of pages | 7 |
| Journal | American Mineralogist |
| Volume | 89 |
| Issue number | 4 |
| Publication status | Published - 1 Apr 2004 |
Abstract
In the present work, we characterize the amphibole Na(NaMg)Mg5Si8O22(OH)2 synthesized at 0.4 GPa and 750, 800. and 850 °C, and 0.5 GPa, 900 °C. Experiments at 800 and 900 °C yielded crystals suitable for single-crystal data collection. Structure refinement shows that synthetic Na(NaMg)Mg5Si8O22(OH 2 has P21lm symmetry at room T. The two non-equivalent tetrahedral double-chains differ in their degree of stretching and kinking. The infrared spectrum of synthetic Na(NaMg Mg5Si8O22(OH)2 has two well-defined absorption bands at 3742 and 3715 cm-1 which can be assigned to O-H bands associated with the two independent anion sites (O3A and O3B) in the structure. The higher frequency band is assigned to the shorter O3B-H2 bond, and the lower frequency band is assigned to the longer O3A-H1 bond. The broader shape of the 3743 cm-1 band is consistent with a stronger interaction of the H2 atom with ANa, which is confirmed by structure refinement. Increasing T of synthesis causes a progressive departure from the ideal stoichiometry via the A□1BMg1 ANa-1BNa-1 substitution, as confirmed by EMPA, structure refinement, and FTIR spectroscopy.
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Geophysics
- Earth and Planetary Sciences(all)
- Geochemistry and Petrology
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In: American Mineralogist, Vol. 89, No. 4, 01.04.2004, p. 640-646.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Synthesis and crystal-chemistry of Na(NaMg Mg5Si8O22(OH)2, a P21/m amphibole
AU - Iezzi, Gianluca
AU - Ventura, Giancarlo Della
AU - Oberti, Roberta
AU - Cámara, Fernando
AU - Holtz, François
N1 - Copyright: Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2004/4/1
Y1 - 2004/4/1
N2 - In the present work, we characterize the amphibole Na(NaMg)Mg5Si8O22(OH)2 synthesized at 0.4 GPa and 750, 800. and 850 °C, and 0.5 GPa, 900 °C. Experiments at 800 and 900 °C yielded crystals suitable for single-crystal data collection. Structure refinement shows that synthetic Na(NaMg)Mg5Si8O22(OH 2 has P21lm symmetry at room T. The two non-equivalent tetrahedral double-chains differ in their degree of stretching and kinking. The infrared spectrum of synthetic Na(NaMg Mg5Si8O22(OH)2 has two well-defined absorption bands at 3742 and 3715 cm-1 which can be assigned to O-H bands associated with the two independent anion sites (O3A and O3B) in the structure. The higher frequency band is assigned to the shorter O3B-H2 bond, and the lower frequency band is assigned to the longer O3A-H1 bond. The broader shape of the 3743 cm-1 band is consistent with a stronger interaction of the H2 atom with ANa, which is confirmed by structure refinement. Increasing T of synthesis causes a progressive departure from the ideal stoichiometry via the A□1BMg1 ANa-1BNa-1 substitution, as confirmed by EMPA, structure refinement, and FTIR spectroscopy.
AB - In the present work, we characterize the amphibole Na(NaMg)Mg5Si8O22(OH)2 synthesized at 0.4 GPa and 750, 800. and 850 °C, and 0.5 GPa, 900 °C. Experiments at 800 and 900 °C yielded crystals suitable for single-crystal data collection. Structure refinement shows that synthetic Na(NaMg)Mg5Si8O22(OH 2 has P21lm symmetry at room T. The two non-equivalent tetrahedral double-chains differ in their degree of stretching and kinking. The infrared spectrum of synthetic Na(NaMg Mg5Si8O22(OH)2 has two well-defined absorption bands at 3742 and 3715 cm-1 which can be assigned to O-H bands associated with the two independent anion sites (O3A and O3B) in the structure. The higher frequency band is assigned to the shorter O3B-H2 bond, and the lower frequency band is assigned to the longer O3A-H1 bond. The broader shape of the 3743 cm-1 band is consistent with a stronger interaction of the H2 atom with ANa, which is confirmed by structure refinement. Increasing T of synthesis causes a progressive departure from the ideal stoichiometry via the A□1BMg1 ANa-1BNa-1 substitution, as confirmed by EMPA, structure refinement, and FTIR spectroscopy.
UR - http://www.scopus.com/inward/record.url?scp=1942531293&partnerID=8YFLogxK
U2 - 10.2138/am-2004-0419
DO - 10.2138/am-2004-0419
M3 - Article
AN - SCOPUS:1942531293
VL - 89
SP - 640
EP - 646
JO - American Mineralogist
JF - American Mineralogist
SN - 0003-004X
IS - 4
ER -