| Popis: |
Attention will be focussed on the following topics and relevant problems concerning the characterization of alkali feldspars. Light optics: textural observations and determination of specific optical properties. Composition and lattice strain: (a) determination of composition of unstrained specimens, (b) evaluation of lattice strain caused by coherency between exsolved phases and determination of composition of strained specimens, (c) composition from K,Na site refinement of X-ray data. Determination of tetrahedral Al contents: (a) from lattice parameters, (b) from T-O distances, (c) from Si,Al site refinement of X-ray data. Single-crystal X-ray diffraction patterns and relationships with TEM techniques: (a) the diagonal association, (b) the antidiagonal association, (c) P21/a structural arrangement. Unanswered questions and suggestions for future work will be underlined. |
