The Mineral and Fuel Industry of Indiana by Kathryn R. Shaffer Mineral and fuel commodities mined in Indiana include common clay and shale, ball clay, limestone and dolomite, construction sand and gravel, industrial sand, sandstone, gypsum, peat, and coal. Depending on the quality and type of limestone, it may be sold as dimension stone for construction of buildings, crushed for use as aggregate, or used in the production of concrete or cement. Crushed stone is also processed into agricultural lime or used for sulfur dioxide removal in coal-fired electric power plants with limestone scrubbing systems or may be finely ground for use as fillers in various products. In addition to agricultural lime, some stone is imported from Michigan and processed by two northern Indiana companies into lime used mostly by the steel industry on Lake Michigan.
Dolomite is sold as crushed stone.
Some has been sold as decorative dimensional stone. A small quantity of sandstone is occasionally produced on demand for small landscaping or construction projects. The clay and shale produced in Indiana is primarily used for cement, concrete blocks, tiles, animal feed, absorbents, plastics, adhesives, or paint. Gypsum is primarily used in production of wallboard and cement. Peat is used for soil improvement, on golf courses, for earthworm culture and by nurseries.