US Silica Holdings, Inc. is a silica sand supplier company. The Company is a producer of industrial minerals, including sand proppants, whole grain silica, ground silica, fine ground silica, calcined kaolin clay and aplite clay. The Company operates in two segments: oil and gas, and industrial and specialty products. The Company�s shipping capabilities include five of the class-one railroads, barge, full truckload, partial truckload and intermodal. The Company�s products include proppants, whole grain silica, ground silica, fine ground silica, testing silica, recreational silica, aplite, kaolin, hydrous kaolin and FLORISIL. It also operates as a research and development specialist for customized products and solutions. The Company serves a range of industries and applications, which includes oil and gas, glass, chemicals, foundry, building products, fillers and extenders, recreation, industrial filtration and treatment, and testing and analysis.