Geo Science Videos: Naming Igneous Rocks

This video, produced by two science educators, describes how hot magma is converted to igneous rocks, one of the three major groups of rocks on Earth. It explains how geologists use texture (grain size) to identify if the magma that formed the rocks cooled at Earth's surface or deep below ground. It then discusses how to can use simple observations of the color of the minerals in the rocks to further categorize them on the basis of their chemical composition (silica content). Finally, you will learn how to identify six common igneous rocks that represent a range of textures and compositions. You will have opportunities to practice identifying the essential characteristics of these rocks at several points during the video. [6:36]