Refractory cordierite ceramic using amorphous rice husk silica was modified by addition of periclase from 5 to 30% by weight, followed by sintering treatment at temperature of 1230 ^oC. The phases, structural changes and physical characteristics of samples were investigated by x-ray diffraction (XRD), followed by Rietveld refinement, differential thermal analysis (DTA), scanning electron microscopy (SEM), and thermal dilatometry.  The results revealed that addition of periclace promoted decomposition of cordierite into spinel, forsterite, and  practically undetected with periclace addition of 10 to 30%. Addition of periclace was found to increase forsterite and decrease spinel. The DTA analyses also demonstrated that in the  samples with periclace addition from 5 to 30% were found the existence of spinel and forsterite as dominant phases. The presence of forsterite and spinel and resulted in increased density, hardness, bending strength and thermal expansion coefficient, as well as decrease porosity. Thermal expansion coefficient of the samples  with periclace addition of 10 to 30%  reach the relatively constant value of  8.2 x 10^-6/ºC, with the main crystalline phases are forsterite and spinel. The presence of these phases suggest the potential use of the modified cordierite as abrasive devices.