Content adapted with permission from the Indiana Geological Survey, a partner in the Natural Heritage of Indiana project. Credit for this article goes to John R. Hill. More information can be found here.

Indiana Limestone, which is a Mississippian-age grainstone of very uniform texture and grade, has gained world-wide acceptance as a premier dimension stone. The Salem Limestone, which is the geologic formational name for this carbonate unit, crops out in a belt that trends southward from Stinesville in Monroe County to Bedford in Lawrence County. The outcrop belt varies in width from about a mile to nearly 10 miles near Bedford.

The earliest known Indiana Limestone quarry was opened southeast of Stinesville in 1827 by Richard Gilbert. In 1929, the zenith of American-stone architecture, Indiana furnished 12 million cubic feet of dimension stone. At present, nine quarries extract the Salem Limestone. Most of the quarries use modern diamond belt saws to dimension the quarry blocks and air bags to turn down the cuts. Individual quarry blocks are broken using the time-honored method of driving steel wedges between half-shell slips or feathers that are placed in holes drilled by pneumatic star bits.

Indiana Limestone is a freestone, which means that it exhibits no preferential direction of splitting and can, therefore, be cut and carved in an almost limitless variety of shapes and sizes. This property allows the stone to be planed, turned on a lathe, sawed, and hand worked to match the requirements of the most demanding architectural designs. Indiana Limestone exhibits three colors: gray, buff, and variegated, which includes patterns of both gray and buff.

Did you know:

• That nearly 2.7 million cubic feet of Indiana Limestone is quarried each year?
• That, although a relatively small industry, the Indiana Limestone industry generates about $26 million annually in revenue?
• That Indiana Limestone can be quarried and milled with greater efficiency, in terms of energy consumed, than most competing building materials?
• That Indiana Limestone has stood the test of time in structures all over the world where its strength, beauty, and durability have made it the material of choice in many older load-bearing structures as well as cladding stone in the modern context?
• That the Indiana Limestone industry employs stone cutters and carvers whose skills in working limestone into complex shapes and into art forms remain world class?
• That the Empire State Building in New York and the US Holocaust Memorial and Museum in Washington, DC are made of Indiana Limestone?

For more information, see The Indiana Limestone Institute of America »