Summary

This collection conta ins the results of a number of investiga­ tions which have been carried out in the Hydrothermal Synthesis Laboratory of the Institute of Crystallography, Academy of Sciences of the USSR; it constitutes a continuation of an earlier collection which appeared in 1968: Hydrothermal Synthesis of Crystals. Problems associated with the synthesis of oxides, simple and complex sulfides, carbonates, silicates, and germanates are consid­ ered, and a great deal of factual material relating to the growth of single crystals of some of these compounds on a seed is presented. Some of the articles pay special attention to the kinetic asp­ ect of the growth of crystals; the conditions of growth are relat­ ed to the morphological characteristics of the growing faces, and the relationship between the habit of the crystals and the oomposi­ tion and constitution of the solutions is considered. A fair number of articles are concerned with the crystalliza­ tion of new compounds, most of which have now been synthesized under hydrothermal conditions for the very first time; these in­ clude ternary chalcohalides of composition AVBvIVVII. zirconates, lithium silicates, and germanates. The collection also contains a description of the apparatus used for precision measurements at high temperatures and pres­ sures. We hope that this publication will present a better idea of the special characteristics of the hydrothermal method of synthes­ izing and .growing crystals, and will prove useful to all those in­ terested in this field of knowledge.