Silica sand (or quartz sand) is made from quartz granule via crushing process. As is a kind of nonmetallic minerals, quartz rock is very hard and wearable. It belongs to silicate minerals of stable chemical properties. SiO2 is the main mineral component. Silica sand is either milk white or in a colorless translucent status. Its hardness is 7; silica sand is brittle and of no cleavage. It has conchoidal fracture and greasy luster. Its density is 2.65; the bulk density is 1.6 at a mesh number of 1-20, and 1.5 at a mesh number of 20-200. The chemical, thermal and mechanical properties are of distinct anisotropy. It is insoluble in acid, and slight soluble in KOH solution. Its melting point is 1750℃.