Different mineral structures can act as mineral reservoirs for the immobilisation of toxic compounds. In the paper different mineral structures will be explained and their potential for incorporation of heavy metals and anions will be shown. The following structures will be explained (Pllmann, 2007): apatites (incorporation of heavy metals, silicate apatites); ettringites (fixation of oxo-anions); layered double hydroxides (fixation of heavy metals, fixation of anions, fixation of organics, sorption materials); and manganese oxides._x000D_
Different possibilities of solid solution and incorporation in crystal structures will be explained and advantages of stable minerals be proved using experiences with real toxic wastes._x000D_
In the process of thermal treatment the formation of primary mineral reservoirs will be shown. The precursor phases (similar to well known cement minerals) react in contact with water to form secondary mineral reservoirs (cement hydration mineral products)._x000D_
The formation condition of primary and secondary mineral reservoirs and their stabilities and incorporation possibilities will be shown._x000D_
Examples for incorporation of various elements are given. Application for water clarification will be outlined.