Which rock type is formed by the cooling and solidification of magma or lava?

Which rock type is formed by the cooling and solidification of magma or lava?

• A. Igneous
• B. Sedimentary
• C. Metamorphic
• D. Mineral

Answer: (A)

Igneous rocks form when molten rock cools and solidifies. When magma cools underground, crystals grow slowly to make coarse-grained rocks like granite; when lava erupts and cools rapidly at the surface, you get fine-grained rocks like basalt or even glassy textures like obsidian. Sedimentary rocks come from sediments that are deposited and cemented together, metamorphic rocks come from existing rocks altered by heat and pressure, and minerals are the building blocks, not a rock type. So the rock formed by cooling and solidification of magma or lava is igneous.

Igneous rocks form when molten rock cools and solidifies. When magma cools underground, crystals grow slowly to make coarse-grained rocks like granite; when lava erupts and cools rapidly at the surface, you get fine-grained rocks like basalt or even glassy textures like obsidian. Sedimentary rocks come from sediments that are deposited and cemented together, metamorphic rocks come from existing rocks altered by heat and pressure, and minerals are the building blocks, not a rock type. So the rock formed by cooling and solidification of magma or lava is igneous.