Indiana is known for its limestone. While Indiana does have some deposits of other minerals like coal and natural gas, limestone is the most valuable rock mined in the state by far.

Here's why limestone is so important:

* Construction: Limestone is a key ingredient in cement, concrete, and aggregate, all vital to building infrastructure.

* Agriculture: Limestone is used as a soil amendment to neutralize acidity and improve fertility.

* Other industries: Limestone is also used in the production of glass, steel, and chemicals.

While Indiana may have some other valuable minerals, limestone is the bedrock of the state's mining industry.