This chapter looks at fossils from a humanistic perspective. Fossil fuels—coal, oil, and natural gas—make up over 80% of our energy sources. They are called fossil fuels because they all come from ancient organic matter that has been buried and then heated over a long period of time. The first activity in this chapter describes the origins and processes of formation of the fossil fuels and guides students in an investigation of the properties of coal and peat. The second activity examines the actual plant fossils in coal balls and makes an important link between fossils of the past and our energy needs today.