Learn about igneous rock classification and how to use the QAPF diagram in this comprehensive video on igneous petrology. Explore the basics of igneous rock composition and grain size, and discover how these features are used for identification. Delve into various classification schemes, including the IUGS QAPF diagram for plutonic and volcanic rocks, as well as the separate classification for ultramafic rocks. Gain insights into the importance of mineralogy in petrology and understand the differences between volcanic and plutonic rocks based on grain size and silica content. Follow along as the video covers modal mineralogy, the QAPF diagram with rock pictures, and the IUGS volcanic classification system. By the end of this 25-minute tutorial, acquire a solid foundation in igneous rock classification methods essential for geologists and earth science enthusiasts.