Natural Cement: Pioneer Hoosier Mineral Industry (HI-08)
Natural cement, made by heating clayey limestone until it melts, and grinding the clinker into powder, was one of Indiana's earliest mineral industries. A converted flour mill at Clarksville started grinding cement in 1832.

Natural cement rock, discovered in the Jeffersonville-Clarksville area in 1826, was used locally for many years. The stone was quarried in open pits from underground mines. By 1870, Indiana was one of the nation's largest cement producers.

One of the first portland cement plants in the U.S. began operating near South Bend in 1877. By the 1920's, production of natural cement had decreased drastically as the superiority of portland cement became recognized. Only one plant still produces natural cement.

Our Hoosier State Beneath Us: Historical