Foreword xiii
the guidance of George V. Wulff. A laboratory on crystal growth is functioning now
at the Geological Faculty of Moscow University headed by Nikolai I. Leonyuk.
In 1970s a versatile laboratory on crystallogenesis was organized by Nikolai P.
Yushkin in Syktyvkar Institute of Geology of the Academy of Sciences. Its director
Askhab M. Askhabov forwarded principal concepts of media structure in relations
with crystal formation. Also, several other scientific centers for crystal growth
investigations successfully operate in different regions of Russia.
As a whole, the tasks of crystallogenesis were unified by a general formula sug-
gested by G. G. Laemmlein half a century ago: “finding the correlative signs
between internal and external morphology of a crystal, its physical and chemical
properties and conditions of its formation in the broadest aspect.”
Last decades of the twentieth century were marked by considerable progress
made in the field of crystallogenesis. Nevertheless, complexity of the problems
involved is still increasing and the branch itself is still developing. It can be
expected that crystallogenetic study enters a new stage of its development, which
consists in combining physicochemical, experimental-methodological and minera-
logical aspects to create a general problem-theoretical concept. Extremely impor-
tant for development of the art is interpretation of phenomena observed during
crystal nucleation, growth, and dissolution, which form the basis for the great
majority of important crystallochemical regularities, minerogenetic, petrologic, and
lithogenic processes, as well as for industrial processes, etc. However, common
approaches do not generally take into consideration the theory of crystallogenesis.
Partly, this is caused by impossibility to supply a clear, obvious, and thorough
explanation for complex phenomena of crystal formation, and partly this is rea-
soned by the fact that the theory has not been developed sufficiently to elucidate
natural phenomena of the utmost complexity.
Since 1980s the author of the present monograph together with coworkers, stu-
dents, and postgraduate students has been conducting systematical investigations,
which have shown that polymineral crystallogenesis is characterized by a number
of characteristic features that cannot be explained within the limits of classical
theory. The processes of polymineral crystallogenesis are complicated by various
forms of synchronized growth and dissolution, interaction between crystals of dif-
ferent phases, and peculiarities of phase equilibria that have not been taken into
account until now. Naturally, elementary processes forming the basis of polymin-
eral crystallogenesis are similar to those extensively studied in simple and binary
systems. The difference consists in greater diversity and singularity of their
combinations.
In the present monograph attention is paid to crystallogenesis in polymineral
media, which is the most complicated process typically occurring in natural envi-
ronments. Previously, the concepts involved in this problem have not been fully
developed and that has naturally led to various misunderstandings. First, there are
some terminological problems, since conventional vocabulary does not cover the
terms invented for all new phenomena. This prompts using mineralogical, crystallo-
genetic, and physicochemical terminology, inventing hybrids and also absolutely
new terms. Probably, some of them are not quite justified, and in future something