Darby finds a rock in her backyard. It has large crystals. She has found _____.

Question

an extrusive igneous rock
basalt
obsidian
an intrusive igneous rock

Answer 1

Darby has likely found an intrusive igneous rock. Intrusive igneous rocks, such as granite, form from magma that cools slowly beneath the Earth's surface, allowing large crystals to form. In contrast, extrusive igneous rocks like basalt and obsidian cool quickly at the surface and typically do not have large crystals.