I used to find fossils as a kid when I grew up outside Cincinnati, Ohio. My mother used to let us look for rocks while she shopped. Rocks tell us about the history of the earth. Rocks show you environmental change through time. Remember, The present is the key to the past.
Rocks are important to our ecomonics because oil and coal are found in rocks.
Other rocks are important building products. Limestone is used in road construction, steel-making, concrete and cement. It's an easy way to find the presence of silt, which in some cases is too fine to be felt by hand. Silt helps identify rocks. A mineral is a naturally occurring substance with a definite chemical structure.