Cinder Cone A cinder cone is made from a volcanic rock, called andesite. Basalt may also be mixed in with the andesite. These cinders may be tiny, like ash or larger, like gravel. When they get blown out of the vent, they harden in the air. They land and pile up around the crater, which causes the steep cone.
Cinder cones wear away a lot easier than shield volcanoes.
Shield Volcanoe A shield volcanoe has such a gentle slope because it is made from many layers of a certain volcanic rock, called basalt, which flows easily when melted. When basalt flows out of the volcanoe, it forms thin layers that slope away from the crater. The Hawaiin islands are examples of the shield volcanoes. Composite Cone A composite cone is made from many layers of cinders between layers of lava. The layers of cinder make the sides of the volcanoes steep.