Fun Facts About Indiana Limestone

• Grand Central Station, the Pentagon, the Lincoln Memorial, Empire State Building, and Tribune Tower are all made of Indiana Limestone.

• Indiana Limestone is known as Salem Limestone, after the exposed areas of stone located near Salem, Indiana.

• Salem Limestone is incredibly chemically pure—it is about 97 percent calcium carbonate.

• Limestone was designated Indiana’s state stone in 1971.

• Until the late 1800s, quarries were not aware that the limestone belt was one continuous strip of rock; because of this, it was known as many local names. These included Bedford Stone, Bloomington Stone, Ellettsville Stone, Salem Stone, and White River Stone.

• The Salem Limestone corridor which runs through Monroe and Lawrence Counties is incredibly deep, reaching 90 feet below the earth’s surface in certain areas.

• Indiana Limestone is made from the countless numbers of carbonate shell debris from Mississippian Period organisms.

• Limestone erodes easier than other types of stone; this has led to Southern Indiana’s characteristically hilly uplands.

• Limestone composes about 15 percent of the Earth’s crust.

• The more groundwater limestone is exposed to, the more “pure” and favorably-colored it becomes. Lower layers of limestone with more water exposure are the type used for building.