Scoria can be found in areas of the Earth where volcanic activity has occurred. Ranging in color from black to dark red, it is an igneous rock riddled with air bubbles. Scoria is created as gas escapes from a volcano and rock solidifies around it.
Scoria builds up around the vent of a volcano. The cone-shaped hill formed by scoria is called a cinder cone. Some parts of the world have large areas with multiple cinder cones called volcano fields. Volcanoes that produce scoria usually have brief eruptions and are not very tall. Scoria is often used in landscaping or as a lightweight aggregate added to concrete.