1 Structures and Structure Modifications of Layer Silicates. - 1. General Introduction to the Structures of Layer and Pseudolayer Silicates. - 2. Some Features of the Structures of Individual Layers. - 3. Use of Structural Polyhedra in the Description and Analysis of Layer Silicate Structures. - 4. Polymorphic and Polytypal Modifications and Repeat Sequence Methods in Layer Silicates. - 5. Regular Structures of Two-Storied Kaolinite-Type Layers. - 6. Regular Structures of Three-Storied Mica-Type Layers. - 7. Regular Structures Made Up of Chlorite Packets. - 2 Experimental Electron-Diffraction Methods of Studying Minerals. - 1. Electron-Diffraction Apparatus. - 2. Preparation of Specimens for Study. - 3. Electron-Diffraction Patterns and Their Analysis. - 3 The Geometrical Theory of Electron Diffraction and Analysis of Clay Mineral Diffraction Patterns. - 1. Theoretical Basis of the Relationship Between the Crystal Lattice and the Diffraction Pattern: The Reciprocal Lattice. - 2. Geometrical Analysis of Electron-Diffraction Patterns. - 3. The Distribution of Reflections on Ellipses on Electron-Diffraction Texture Patterns from Layer Silicates. - 4 The Determination of Intensities in Layer Silicate Diffraction Patterns. - 1. General Comments. - 2. Analysis of Intensities in the Investigation of Layer Silicate Structures. - 3. Wave-Scattering by a Silicate Layer Sequence. - 4. The Distribution of Intensities in Layer Silicate Structure Modifications. - 5. Geometry of Layer Silicate Structural Features as Revealed Through the Distribution of F or | F | 2. - 6. Effect of Variations in Chemical Composition on the Intensity Distribution in Layer Silicates. - 5 Experimental Electron-Diffraction Studies of Clays and Related Minerals. - 1. The Determination of Crystal Structures. - 2. Uncertainty in theNacrite Structure. - 3. Electron-Diffraction Data on Sepiolite and Palygorskite Structures. - 4. Investigations Using the Microdiffraction Method. - 5. Some Achievements of Electron-Diffraction Studies of Clays Clay Minerals and Related Layer Silicates by the Oblique Texture Method. - 6. Possible Fields of Application of the Electron-Diffraction Method in the Study of Minerals Which Are Not Layer Silicates. - Literature Cited. Language: English