When evaluating Feldspar Powder, the most critical factors are chemical composition and particle size distribution. For the ceramic and glass industries, you must verify the Potassium Oxide (K2O) or Sodium Oxide (Na2O) content, as these determine the fluxing capability. Additionally, monitor the Iron Oxide (Fe2O3) levels, which should ideally be below 0.1% for high-quality white ceramics or clear glass to prevent discoloration. Ensure the mesh size (e.g., 200, 325, or 500 mesh) aligns with your specific production requirements for optimal melting and reactivity.