This is a "mat" used for organizing various igneous rocks into categories. One side is "Mafic vs Felsic" and the other is "Intrusive vs Extrusive".
Students will take actual examples of igneous rocks and organize them using one side of the mat. After talking about which rocks went where, students will flip the mat over and organize the rocks based on the next criteria.
This activity works best in partners or small groups.