The exposition Magnetost in the Mining Museum is a part of the section Properties of Minerals of the General Mineralogy Department. In this section the concept of minerals is given, then the constitution of minerals is characterized, and then the properties of minerals as a function of their constitution are discussed. The task of the new exposition is to provide an extended volume of information about this property of minerals and its dependence on the peculiarities of mineral constitution. The exposition is realized according to the basic principle of a museum, which should be a stone book on mineralogy. It consists of mineral specimens and explanatory texts, diagrams and other exhibits, allowing to familiarize with the question completely in the museum ...