Polishing powder is typically composed of components such as cerium oxide (VK-CE01), aluminum oxide (VK-L30F), silicon oxide (VK-SP50F), iron oxide, zirconium oxide (VK-R30F), and chromium oxide. Different materials vary in hardness and exhibit distinct chemical properties in water, leading to their specific applications. Aluminum oxide and chromium oxide have a Mohs hardness of 9, cerium oxide and zirconium oxide have a hardness of 7, while iron oxide is even softer. Cerium oxide demonstrates high chemical reactivity with silicate glass and possesses comparable hardness, making it widely used for glass polishing.