Crystal structure of litvinskite: A new natural representative of the lovozerite group
| Autor: | Yu. K. Egorov-Tismenko, I. A. Ekimenkova, Natalia A. Yamnova, Igor V. Pekov |
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| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | Crystallography Reports. 46:190-193 |
| ISSN: | 1562-689X 1063-7745 |
| DOI: | 10.1134/1.1358391 |
| Popis: | A new representative of the lovozerite group—Na, Zr, Mn-silicate litvinskite (Na, H2O, □) 3(□, Na, Mn2+)Zr[Si6O12(OH)3(OH, O)3]—was discovered in ultraagpaitic pegmatites from the Lovozero massif. The crystal structure of the mineral was solved on an automated Syntex P \(\bar 1\) diffractometer (MoK α radiation, 1398 reflections, 2θ/θ scanning technique, anisotropic refinement to R hkl = 0.065). The unit-cell parameters are a = 10.589(7) A, b = 10.217(8) A, c = 7.355(5) A, β = 92.91(5)°, V = 794.6(9) A3, sp. gr. Cm, Z = 2, d calcd = 2.63 g/cm3. The structure of the mineral consist of a three-dimensional framework of discrete six-membered rings of Si-tetrahedra linked to isolated Zr-octahedra. The framework cavities are occupied by Na cations. The litvinskite composition and the structure differ from all known natural and synthetic compounds of the lovozerite group, which supports the assumption about diversity of mineral types in this group. |
| Databáze: | OpenAIRE |
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