Highly dispersed alpha-Fe2O3 nanoparticles were immobilized onto crystalline glass microspheres for the first time to be heterogeneous Fenton catalysts (FeCG) with favorable activity. The average particle size of the supported iron oxides ranges from 2.6 to 6.5 nm and can be achieved controllably with great ease. Typically through hydrothermal treatment it was found that an amorphous glass support develops into mixed crystals of primitive SiO2 CaSi2O5 and Ca2MgSi2O7 with-480% improvement in specific surface areas. Most importantly after Fe loading not only OH. but also HO2. radical species with high intensity were generated for FeCG also OH. while OH. alone was produced for commercial alpha-Fe2O3 in the presence of H2O2 thus accelerating the redox recycling between Fe(II) and Fe(III) and presenting much superiority in the azo dye AO7 decoloration. The pseudo zero-order reaction constant was determined to be 0.384 mg/(L.min) an,similar to 65.5% improvement over that of commercial alpha-Fe2O3 under the same experimental conditions. Only 1.26 mg/L Fe leaching was detected under optimum conditions in addition to simple catalyst recovery by gravity. No remarkable decrease in the AO7 decoloration efficiency was observed after six cycles indicating the favorable stability.