pyroclasticadjective
uk/ˌpaɪ.rəˈklæs.tɪk//ˌpaɪ.rəˈklæs.tɪk/specializedconsisting of or relating to small pieces of rock from a volcano:
In 1902, on the Caribbean island of Martinique, a single pyroclastic flow killed more than 29,000 people.
Rocks like pumice, which are ejected as broken, solid fragments rather than in liquid form, are known as pyroclastic rocks.