Igneous rocks are formed by excessive heat and pressure.

The story behind the answer

False. Igneous rocks form when molten rock—magma underground or lava at the surface—cools and solidifies. Heat is involved in the melting, but “excessive heat and pressure” is the hallmark of metamorphic rocks, which are transformed from existing rocks without fully melting.

To remember: Igneous = “ignite” (fire) → born from melted rock. Metamorphic = “meta” (change) + pressure/heat → changed in the solid state. Intrusive igneous rocks (like granite) cool slowly beneath the surface, growing large crystals; extrusive rocks (like basalt or obsidian) cool quickly at or near the surface, forming fine-grained or glassy textures.