In this paper, the influence of MgO and CaO content on the quality of technical ceramics (which originally represents the Al2O3 - SiO2 - CaO - MgO system) has been investigated. Therefore, quality tests were performed on samples where the contents of CaO and MgO were taken as variable values. Based on the obtained test results and their analysis, certain characteristics of ceramics are defined with the different percentages of individual oxides content in 98.2 - 99% Al2O3
