1.This is 80-120 Quartz Sand. 2.It is used in inner layer for shell-making. 3.It is used in investment casting. 1.The Quartz sand`s main component is quartz.2.the density is 2.65 grams per square centimeter, Mohs hardness is 7, the crystallization is 60,000 grain system, the appearance is white, blue gray, gray and so on. Mainly used in glass, foundry industry, metallurgical industry, ceramic ...