It is the material ejected by a volcano during an eruption. The name comes from the Greek 960; 965; 961; ( pyr "fire" ) 954; 955; 945; 963; 964; 959; 962; ( klastós "broken") . See tephra, lava.
Incandescent material that the volcano throws up during an eruption. It can be represented by fire bombs, ash, incandescent rocks, lapilli.