Principal minerals produced in order of value are coal, crushed stone, natural gas, and petroleum.
Deposits of fluorspar and zinc are also located in Kentucky. Kentucky's remaining coal resources in seams greater than 14 inches in thickness are 92 million tons. Because of the rapid depletion of supplies of natural gas and oil, and the use of coal in electric generating plants, Kentucky coal is expected to be an important factor in meeting the nation's future energy needs. About 79 billion cubic feet of natural gas is produced annually in Kentucky. More than 80 percent of the state's total production over the years has come from the Big Sandy gas field, a seven county area along the eastern edge of the state.