Garnet sand (water knife sand), also known as natural diamond, lines are silicate minerals. Hardness can reach 6.8 - 7.9 degrees (Morse), through hydraulic sorting, mechanical processing, selection grade, etc made of a direct role can not calcined natural abrasives, grinding force slightly lower than the furnace white fused alumina, but its toughness, the characteristics of a shell fracture, it is widely used in water jet cutting, grinding glass, leather, sandpaper, and metal industrial sandblasting the rust and other industrial abrasive materials indispensable.