A method of preparing a precursor or cordierite-forming particulate raw material mixture is improved upon by characterizing the talc particles utilized in the raw material mixture in accordance with a Morphology X-ray Diffraction Index or the surface area of the talc particles. Talc particles having a predetermined or desired Morphology X-ray Diffraction Index or surface area are utilized in preparing the raw material mixture. A cordierite article is produced having pores therethrough, which pores have shapes that are "blocky" or "platy" as a result of the talc morphology. "Platy" pores in the fired cordierite article result in higher Water Absorption values and an increase in coatability by high surface area washcoat and catalyst; conversely, "blocky" pores result in lower Water Absorption values and a decrease in coatability by high surface area washcoat and catalyst.