     OGRANKA - description.

     The demonstration of functioning:

     zapusk.bat KVARTZ_ 2.0
     zapusk.bat BERYLL_ 2.0
     zapusk.bat TEST_KUB 1.0

     The principles used in the program:
     We specify the geometry of the crystal cell, symmetry, indices of
faces, and rates of their growth. The program OGRANKA finds the "cutting"
of the crystal (vertices and branches) and draws it on the screen. The
program OBRAB makes auxiliary operation (determines the faces). The
program VYKROJKA "wraps" the faces to form "flat pattern" which can be
transferred to paper with millimeter grid, cut off and glued to obtain
the model of the crystal form.
     I recommend one to compare the forms which the program generates
with the pictures of crystals of quartz (typical side faces) and beryll
(so called "emerald crown") given in manuals and encyclopaedies.
     Disadvantages and absent features:
     (1) Only some of 32 point groups are described; the problem is
that, in trigonal and hexagonal symmetries, the pairs axis/plane can be
oriented both along or between translations, so we must write two
varians for such groups (and, in some cases, third variant -
rhomboedric). In this connection, the indices of experimentally
observed faces for quartz seem to be invalid (I hope that this problem
will be corrected later).
     (2) For beryll, we use arbitrary sizes of the elementary translations,
so, strictly saying, we have the form not for beryll but for some
fictive crystal which just resembles beryll (I would be grateful for
journal reference, lattice parameters etc. to correct this imperfection).

