U.S. Silica Holdings, Inc. (U.S. Silica) is a domestic producer of commercial silica, a specialized mineral that is an input into a range of end markets. The Company operates in two segments: Oil & Gas Proppants, and Industrial & Specialty Products. In the Oil & Gas Proppants segment, the Company serves the oil and gas recovery market providing fracturing sand, or frac sand. The Industrial & Specialty Products segment consists of over 250 products and materials. In its end market, oil and gas proppants, its frac sand is used to stimulate and maintain the flow of hydrocarbons in oil and natural gas wells. Its silica is also used as an irreplaceable raw material in a range of industrial applications, including glassmaking and chemical manufacturing. The Company produces and sells a range of commercial silica products, including whole grain and ground products, as well as other industrial mineral products.