The physical and chemical profile of opal-cristobalite rock - gaize was researched. The analysis results show that the investigated rock is long-range sorption product. The thermal, chemical (acidic-type, alkaline) modification tha same as the organosilicon compound modification were carried out. the results of benchmarking study of physical and chemical profile of natural and modified gaizes show that in process of modification the opportunity for sorpion characteristics enlargement is produced.