Garnet sand ZW Garnet Sand is natural almandite garnet ,due to its low dust,high hardness,,high bulk density,heavy specific weight,long working life,good shape edges and no free silica,it can be widely used in sand blasting, water jet cutting and water filtration. Physical Characteristics Hardness 7.5 - 8.0 Mohs Bulk density 2.34 g/cm3 Specific gravity 4.10 g/cm3 PH 7 Conductivity