Over the years, limestone has proved itself to be a high-quality material, capable of withstanding time and weather exposure. Nearly 80 percent of the dimension limestone used in the United States is quarried in Indiana. Indiana limestone, formed more than 300 million years ago, is essentially composed of sedimentary deposits of shellfish. The stone is classified into two general colors, gray and buff, and four grades based on grain size.
A 7-foot-long arm saw with a continuously rotating diamond blade cuts the stone from the natural sedimentary bed. Large front-end loaders lift limestone blocks to store them for "seasoning." Limestone's volume changes because, as it is quarried, the stone decompresses. Seasoned stone blocks are cut and fabricated to size.
Because of its natural uniformity of composition, texture, and structure, Indiana limestone can be shaped and textured by machine-planing or hand-chiseling in any direction.
Limestone can be finished with sandpaper. Final product shapes are limited only by the ability of the craftsperson. Limestone's softness is ideal for sculpting, yet the material is durable for years of service if properly installed.
The performance of Indiana limestone in water runoff and acid rain is reported to be very good. Limestone's reputation for quality and durability should continue.