earth rocks soil

            rock:a naturally formed solid in the crust, made up of one or more mineral.

                igneous rock:a rock formed when melted rock material cools and hardens.

                 sedimentary rock:a rock made of bits of matter joined together.

                           fossil:any remains or inprint of living things of the past.

      metamorphic rock:a rock formed under heat and pressure from another kind of rock.

                             humus:decayed plant or animal material in soil.

                   pollution:adding any harmful subtances to earth land, water, or air.

     rock cycle:rocks changing from one form into another in a never- ending series of processes.