Igneous rock was once hot liquid inside the earth. Rock that erupted from volcanoes and cooled on the surface is called extrusive igneous rock. Igneous rock that cooled more slowly inside the Earth is called intrusive. Apache Tear and the Hawaiian Islands are mainly igneous rock.
These ingredients will form the molten rock.
Place the marshmallows and butter in a pan. Stir and melt. Add the rice krispies. Stir.
Place a cup of the warm, rice krispy mixture on the waxed paper square. Make sure your hands are sprayed with cooking oil. Sprinkle and roll into the mixture other ingredients like raisins, chocolate chips, nuts, M&M's with your hands. These ingredients will form the rock surface.
After it cools and hardens, you have an edible igneous rock!