Limestone is of rather low value, but nevertheless it is probably the most important mineral. It is mined and used in large amounts, which often conflicts with the protection of karst areas and caves.
In history man used first the flint nodules, which are common in limestone. Later, after he became resident he used the rock for building purposes. Various kinds of limestone and marble were used for walls, pillars and much more. The soft rock was used to produce sculptures. Even limestone roofs and floors were built.
With the increase of technology many more usages of limestone were found. It is burnt in kilns to produce lime, white wall color, and finally cement for concrete. It is needed to produce glass, porcelain, or as addition in the melting of many metals. It is used to purify coal and the waste gas of power plants using carbon based fuel. Limestone neutralizes many toxic substances, especially sulfur oxide and sulfur dioxide. In combination with sulfur it is converted into gypsum.
Limestone is typically quarried, as it occurs in huge sedimentary layers, and as mining is to expensive.