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 ...

The presence of hornblende in slags is of great interest to mineralogists, petrologists and metallurgists. In the studied titaniferous slags, either no mineral is found that is similar to the previously described basaltic hornblende or is not amphibole at all, or it turns out that the mineral identified in the first study as basaltic hornblende is actually olivine, a member of the series of isomorphic compounds Mg₂SiO₄ — Fe₂SiO₄ (maybe with admixtures of some other orthosilicate molecules). This shows that all the assumptions that were made above when accepting the presence of amphibole in slags as a fact are incorrect: these titaniferous slags are more refractory and more viscous than the hypothetical slag with basaltic hornblende. With this article I would like to show the importance of the issue of the possibility of crystallization of amphiboles in slags and the need for special careful studies of crystalline formations in slags that are more or less similar to amphibole. It seems that in order to accurately establish the possibility of crystallization of minerals of this group in factory slags, those crystalline precipitates that are identified as amphibole must be examined with X‑rays.

The aim of our synthetic experiments was to artificially obtain individual components of stone casting in a well-individualized form and in sufficient quantity. We were to synthesize, first, those minerals that were identified by petrographers during microscopic examination of stone casting, and second, those minerals whose presence in the casting could only be assumed. The latter might be present in the form of microlites and could not be determined optically, but could be detected by X-ray diffraction studies of the stone casting. The minerals we synthesized were to be subjected to X-ray diffraction analysis in order to obtain standard Debye patterns (reference patterns) necessary for interpreting the Debye patterns of stone casting. In accordance with this task, the synthesis method chosen was the crystallization of minerals from the corresponding melts.