Known commonly as proppant, or " frac sand " Industrial sand is pumped down holes in deep well applications to prop open rock fissures and increase the flow rate of natural gas or oil. In this specialized application round, whole grain deposits are used to maximize permeability and prevent formation cuttings from entering the well bore. Silica's hardness and its overall structural integrity combine to deliver the required crush resistance of the high pressure present in wells up to 2,450 meters deep. Its chemical purity is required to resist chemical in corrosive environments.