| Abstract: | Raman analyses of single crystals of ikaite, CaCO3??6H2O, synthesized in a diamond-anvil cell at ambient temperature yield spectra from 0.14 to 4.08 GPa; the most intense peaks are at 228 and 1081 cm-1 corresponding to Eg (external) and A1g (internal) modes of vibrations in CO32- ions, respectively. These are in good agreement with Raman spectra previously published for ikaite in powder form at ambient temperature and pressure. Visual observations of a sample consisting initially of a mixture of calcite + water in a hydrothermal diamond-anvil cell yielded a P-T phase diagram up to 2 GPa and 120 ??C; the boundary for the reaction ikaite ??? aragonite + water has a positive slope and is curved convexly toward the aragonite + water field similar to typical melt curves. This curvature can be explained in terms of the Clapeyron equation for a boundary between a solid phase and a more compressible liquid phase or largely liquid phase assemblage. |
| Genre: | Article |
| ProdID: | 70027699 |
| Citation Author: | Shahar, A.; Bassett, W. A.; Mao, H. -K.; Chou, I. -M.; Mao, W. |
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| Citation End Page: | 1839 |
| Citation Issue: | 11-12 |
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| Citation Language: | English |
| Citation Larger Work Title: | American Mineralogist |
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| Citation Number Of Pages: | 5 |
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| Citation Search Results Text: | The stability and Raman spectra of ikaite, CaCO3??6H2O, at high pressure and temperature; 2005; Article; Journal; American Mineralogist; Shahar, A.; Bassett, W. A.; Mao, H. -K.; Chou, I. -M.; Mao, W. |
| Citation Start Page: | 1835 |
| Citation Volume: | 90 |
| Citation Year: | 2005 |
| Type: | citation/reference |
| Text: | The stability and Raman spectra of ikaite, CaCO3??6H2O, at high pressure and temperature; 2005; Article; Journal; American Mineralogist; Shahar, A.; Bassett, W. A.; Mao, H. -K.; Chou, I. -M.; Mao, W. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| URL (DIGITAL OBJECT IDENTIFIER): | http://dx.doi.org/10.2138/am.2005.1783 |
| Date Other: | Sat, 1 Jan 2005 00:00 -0600 |
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