火成岩 (Hóe-sêng-giâm) (火成岩) 是 (sī)岩漿 (giâm-chiuⁿ)抑 (ia̍h)熔岩 (iông-giâm)冷卻 (léng-khiok)佮 (kap)凝固 (gêng-kò͘)了後 (liáu-āu)所 (só͘)形成 (hêng-sêng)的 (ê)一 (chi̍t)款 (khoán)岩石 (gâm-chio̍h)。火成岩和 (hām)堆積岩 (tui-chek-giâm)佮變成岩 (piàn-sêng-giâm)是岩石圈 (gâm-chio̍h-khoan)內 (lāi)，三 (saⁿ)款主要 (chú-iàu)的組成 (cho͘-sêng)岩石。到今 (Kàu-taⁿ)已經 (í-keng)發現 (hoat-hiān)700外 (goā)獎 (chióng)火成岩，大半 (toā-poàⁿ)攏 (lóng)是地殼 (tē-khak)中 (tiong)的岩石。捷看 (Chia̍p-khoàⁿ)的火成岩有 (ū)花崗岩 (hoa-kong-giâm)，安山岩 (an-san-giâm)佮玄武岩 (hiân-bú-giâm)。
