Ceramics-Silikáty 63, (4) 413 - 418 (2019)

Because nature presents 'a laboratory of chemical equilibria', the examples and patterns taken from nature can be used in the education of general and inorganic chemistry. We have compiled the collection of elements and their stable natural forms and we are going to use it in the undergraduate seminars of inorganic chemistry. Here, we propose some trends in physical and chemical properties of elements and compounds that can be demonstrated in the seminars standing in front of our collection (e.g. trends in melting and boiling points, stable oxidation states, bonding preferences of elements). In current overflow of electronic educational materials, such a visual activity can be refreshing for both students and teachers. And last but not least, the collection and this article is meant as our contribution to the 150^th anniversary of Dmitriy Ivanovich Mendeleev's presentation of the periodic table.