This article presents the results of laboratory tests of the physical and mechanical properties of various types of sandstone selected from ten quarries from Carpathian flysch. The parameters were used to evaluate the quality of the sandstone and its suitability for use as armourstone in accordance with applicable standards and quality guidelines. The requirements of the BN-79/8952-31, EN 13383-1:2003 and the CIRIA, CUR, CETMEF (2007) standards were compared. Sandstone can display a large variability of parameters depending on its origin. This, in turn, results in a varying degree of its susceptibility to the destructive effects of water and climate.

The open-cast nature of deposit exploitation means that apart from the extraction of the main mineral, rocks are also found in its vicinity. Their nature, raw material quality and geological and mining conditions allow them to be used in various branches of the economy. Hence, it seems that more attention should now be given to these rocks. However, the long-term, open-cast mining operations involving Bełchatów lignite ultimately necessitated basic, raw-material-related research on the deposits accompanying the lignite as the main mineral. The presented work shows the state of the recognition of rocks lying in the Mesozoic–Neogene contact zone in the Bełchatów lignite deposit as well as their petrographic nature and possible directions of their use. Attention was drawn to the lithological diversity of the studied rocks and diagenetic processes that contributed to the impact on their physical and mechanical characteristics. Based on the analysis of the literature, the current state of utilization and development as well as the balance of accompanying rock resources in the Bełchatów lignite deposit are presented.

Today, it would seem very important from various economic points of view for utilization and management of the aforementioned rocks encountered as open-cast lignite mining to take place. Natural resources are protected where the area mined is kept in check, and there is economic significance to any increasing in the supply of minerals, or materials made from them. The level of profitability for economic entities that exploit lignite deposits may obviously be raised in this way, and environmental goals can also be served if some of what is extracted can be transformed into environment-friendly materials.

This paper presents laboratory analyses of the influence of an acidic environment, salinity and temperature change are able to exert on the geomechanical properties of the opoka-rocks. This rock material, deriving from four sites in East–Central Poland, was found to be variously resistant to factors like the destructive action of water-soluble salts and the effects of an acidic environment, on account of the actuallydiverse nature of the rocks in question. Ultimately, the work offered a basis for a distinction to be drawn between the light opoka-rocks present at the Annopol and KazimierzWielki sites, and the heavy opoka-rocks from Bochotnica and Krasnobród, in terms of both textural and physical-mechanical features. The heavy opoka-rocks from Krasnobród proved least resistant to an acidic environment, which left strength reduced significantly. This kind of rock also experiences both an increase in porosity and absorbability and a decrease in weight. Furthermore, the influence of an acidic environment on aesthetic features of the examined rocks was in all cases negative, salts formed a patina on surfaces that obscured original structural and textural features. None of the tested types of rock presented resistance to the crystallization pressure such salt is able to exert.