This series could be considered convenient reference booklets, each relating statistics for a geologic commodity found in Indiana. The first directory contained information on the producers of mineral raw materials -- including coal, but not oil and gas -- such as management, location, kinds of openings, geology, equipment, capacity, products, and production statistics. Later, industrial mineral commodities were combined into a single directory to include cement, clay and shale, crushed stone, dimension limestone, dimension sandstone, gypsum, lime, peat, construction sand and gravel, industrial sand, and slag. The information pertaining to coal mines and producers was compiled in a separate directory. The earliest directories used a black-and-white Docutek printing process.; however, the most recent directories were created digitally, using limited color.
