Produced by eruption; as, eruptive rocks, such as the igneous or volcanic.

An eruptive rock.

igneous rock produced by eruption and solidified on or near the earth's surface; rhyolite or andesite or basalt; "volcanic rock includes the volcanic glass obsidian"

of igneous rock that has solidified beneath the earth's surface; granite or diorite or gabbro

or igneous rock: rock deriving from magma consolidation; comprise plutonic rocks and volcanic rocks.