Coal fueled the Industrial Revolution and, as a result, changed the course of human history. However, the geologic history of coal is much, much longer than that which is recorded by humans. In your classroom, the coal cycle can be used to trace the formation of this important economic resource from its plant origins, through its lithification, or rock-forming changes, to its final recovery as a fossil fuel. This article describes how you can explore the interconnectedness of the coal, carbon, hydrologic and rock cycles with a close look at how peat is transformed by pressure over time.