Kentucky State Mineral

Coal

Adopted on July 15, 1998

Kentucky's State Mineral is coal. Kentucky ranks as one of the top three producers of coal in the United States, with 150 to 160 million tons of annual production. Coal is mined in two coal fields; the Western Kentucky Coal Field and the Eastern Kentucky Coal Field. Coal is mined because coal is a rock that burns. Most of the coal mined in Kentucky is burned to produce electricity at power plants.

2.094 State Mineral.
Coal is named and designated as the official mineral of Kentucky.
Effective: July 15, 1998
History: Created 1998 Ky. Acts ch. 230, sec. 1, effective July 15, 1998

In 1998, students from Louisville petitioned the State Legislature to make coal the official State Mineral. One problem is that scientifically coal is a rock, not a mineral. Minerals are the building blocks of rocks. Rocks are composed of many minerals. But legally, coal is considered a mineral resource and is taxed as a mineral. The legislature passed the resolution in the summer of 1998, and coal is now the official State Mineral of Kentucky.

Coal is a readily combustible rock containing more than 50 percent by weight of carbonaceous material, formed from compaction and induration of variously altered plant remains similar to those in peat [adapted from AGI's "Glossary of Geology"]. Most coal is fossil peat. Peat is an unconsolidated deposit of plant remains from a water-saturated environment such as a bog or mire; structures of the vegetal matter can be seen, and, when dried, peat burns freely [adapted from AGI's "Glossary of Geology"].

The numerous layers of coal beds in both of Kentucky's coal fields are intermixed with shale and sandstone (and rarely with thin limestones). Most of the major coal beds (there are about 45 to 50 in eastern Kentucky) were formed as widespread peat swamps or mires during the Pennsylvanian Period. During the Pennsylvanian Period the area that is now Kentucky was near the equator and had a climate much like that of modern Indonesia. Tropical climates allowed lush vegetation to accumulate into widespread peats.

All the mined coal in Kentucky is bituminous. The original peat deposits or layers that later became coal were laid down with other sediments during the Pennsylvanian Period (sometimes called the Coal Age). The Pennsylvanian Period started about 323 million years ago, ended about 290 million years ago, and lasted about 33 million years. If you want to learn more about life in the Pennsylvanian peat swamps, see the Pennsylvanian fossil page.

The lignites from the Jackson Purchase Region come from a variety of deposits from the late Cretaceous Period (part of the Age of Dinosaurs; the coals were deposited as peats as early as 70 million years ago) through the Tertiary Period (till about 10 million years ago).

Difference

Minerals: Minerals are naturally occurring inorganic elements or compounds that have an ordered internal structure and characteristic chemical composition, crystal form, and physical properties. For example, quartz is a mineral as is copper.

Rocks: Minerals combine to form rocks like granite, basalt, and sandstone. Rocks can also be composed of solid organic matter, coal is an example.

Gems: Gems are especially fine ("gem quality") mineral specimens that have few flaws in their internal structure and exhibit superior color. These high-quality minerals are typically cut and used in jewelry.