Igneous rock forms from molten rock that cools and hardens either below or on Earth’s surface. Extrusive igneous rocks have small or no crystals, resulting in fine-grained or glassy textures and include pumice, obsidian, and basalt. Intrusive igneous rocks have larger crystals and a coarser texture and include granite.
The student will investigate and understand the rock cycle as it relates to the origin and transformation of rock types and how to identify common rock types based on mineral composition and textures. Key concepts include a) igneous rocks; b) sedimentary rocks; and c) metamorphic rocks.