Research output: Contribution to journal › Article › peer-review
The Cs-bearing (∼ 3.5 wt % of Cs 2 O in average) analcime from the Mariinskoe deposit (the Urals Emerald Mines) occurs in well-formed tetragon-trioctahedron colorless or milky-white crystals from 1 to 7 mm in size. Most often the mineral overgrows on albite or phrenite and has the later hydrothermal origin. Single-crystal X-ray diffraction study revealed its cubic symmetry, space group Ia3d, a = 13.714(2) A, V= 2579.0(6) A 3 . Crystal structure was solved to R 1 = 0.037 on the basis of 157 independent reflections with F > 3σ(F). The crystal chemical formula of analcime based on the refined site-scattering factors Na 0.78 [(H 2 O) 0.92 Cs 0.08 ]Al 1.08 Si 1.92 (O 5.78 OH 0.22 ) is in well agreement with the formula calculated on the base of electron-microprobe data: Na 0.79 [(H 2 O) 0.95 Cs 0.05 )Al 0.98 Si 2.02 (O 5.86 OH 0.14 ). Substitution in the extra-framework part corresponds to the scheme Na + + H 2 O = + + Cs + . We revealed the optical anisotropy of cubic analcime which can be explained by the deficiency of water molecules.
Translated title of the contribution | ANALCIME OF THE MARIINSKOE DEPOSIT (URALS EMERALD MINES, THE MIDDLE URALS): CHEMICAL COMPOSITION AND CRYSTAL STRUCTURE |
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Original language | Russian |
Pages (from-to) | 111-120 |
Number of pages | 10 |
Journal | Zapiski Rossiiskogo Mineralogicheskogo Obshchestva |
Volume | 146 |
Issue number | 4 |
State | Published - 1 Jan 2017 |
ID: 42535199