The mapping of mineral deposits is one of the most important objective methods for their study. This work is devoted to the development of rational mapping methods, treating this issue in general terms. The first impetus for this work was the pressing need for a rationally constructed map of the Altai polymetallic deposits. The necessity of such a map became evident already in the early years of the Geological Committee's research in the Altai, and at that time work was undertaken by both of us in two directions: mapping methodology was developed, and literary, archival, and new unpublished material from the Altai workers of the Geological Committee — necessary for compiling a map of the Altai deposits —was collected. This article is the result of the work carried out in the first direction.

Crystallization of this compound was carried out at a temperature of about +20°C from solutions in methyl alcohol, in which it dissolves quite easily even in the cold. Solubility increases upon heating. A total of 57 crystals were examined. The results of the examination are presented in the table (see the article).