The paper presents the results of the study dealing with improving the physical and mechanical properties of building ceramics samples: mean density, compressive strength, wear resistance, impact resistance, water absorption, thermal conductivity coefficient, and frost resistance. In the study the organic-mineral additive based on industrial wollastonite with the superplasticizer S-3 was used. The most functional amount of the applied additive, as well as the optimal volume of water in the molding mixture and the firing temperature were determined with the method of experiment mathematical planning. In the course of the studies the specifics of the organic-mineral additive influence on the properties and structure of building ceramics are revealed. The findings are attested by electron microscopy data. The application of the organic-mineral additive improves the performance characteristics of building ceramics samples.