When purchasing Kyanite for industrial use, the primary focus should be on Al2O3 (Alumina) content, which typically ranges from 54% to 62%. Higher alumina content signifies better refractory properties. Additionally, monitor the Fe2O3 (Iron Oxide) levels, which should ideally be below 1.0% for high-quality ceramics and refractories to prevent discoloration. The particle size distribution (mesh size) is also critical; common requirements include 35 mesh, 48 mesh, or 100 mesh depending on whether it is used for kiln furniture, brake linings, or precision casting.