noun
igneous rock
Geological term for rock formed from cooled magma or lava. Used in scientific and educational contexts.
花崗岩は火成岩の一種です。
Granite is a type of igneous rock.
変成岩 is metamorphic rock, formed by heat and pressure altering existing rock, while 火成岩 is igneous rock, formed directly from magma or lava.
Compound of 火成 (kasei, 'igneous formation') + 岩 (gan, 'rock'). 火成 is itself from 火 (ka, 'fire') and 成 (sei, 'become, form').