The article is dedicated to the assessment of mineral raw materials of Latvia from the point of view of composition and characteristic properties for application to specific ceramic or other material development. The study aims at providing the insight into the present situation of the chemically treated 2:1 illite/smectite Latvian clays from their application viewpoint, based on the experimental results of their reactive ability to develop/not develop geopolymers, as well as on the effect of chemical and biological activation by Ps.fluorescensAM-PS11 on phase composition, structure and ceramic properties of sintered ceramic materials. The use of geopolymer method, i.e., treatment of clay with different concentration alkay solutions leads to a conclusion that each studied clay/clay mineral ‘reacts’ in a different way on the chemical treatment from the point of view of the ceramic properties and mechanical strength. There is no conclusive evidence on the formation of geopolymers in chemical treatment of illite clays. It is concluded that the sintering temperature of chemically treated clays significantly reduces to 200-3000C, and sufficiently high compressive strength exceeding 25 N/mm2 is reached. Comparison of the treatment of raw clay by a suspension of Ps.fluorescensAM-PS11 and alkaline activation shows the slight structural changes mainly characterized by water link changes in illite structure together with decrease in diffraction peaks of all crystalline phases of illite and kaolinite by alkali treatment, but not biological activation. This impact is mainly exerted on such technological properties as shrinkage and plasticity. The effect of mineral raw materials on the formation of new ceramic materials is recognized and applied to the development of hightemperature porous, cordierite and mullite – ZrO2 ceramics.