When sourcing polished tiles, you must prioritize Water Absorption Rate, which should be ≤0.5% for porcelain tiles to ensure durability and frost resistance. Pay close attention to the Mohs Hardness scale; a rating of 6 or higher is ideal for high-traffic areas to prevent scratching. Additionally, verify the Glossiness level, where premium tiles typically achieve a score of 90 degrees or above for a mirror-like finish. For safety, ensure the Coefficient of Friction (COF) meets your local building codes, especially for commercial flooring.