Direct experience shows that the phenomenon of crystallization is a very complex phenomenon in which various factors play a decisive role. Although, according to Steno's law, the angles between the corresponding faces in crystals of the same substance are constant, the appearance of forms that determine crystallization is far from being completely constant. At first glance, even the opposite appears to be true. From the same substance you can have crystals with a very limited number of pairs of faces, in exceptional cases not even reaching three, but you can also have crystals with a very rich combination. The forms that make up the combination are also very diverse in their development, and the very forms that in one case are predominant in size, in other cases fade into the background or are even completely suppressed by other forms.
