In this activity, students examine garden variety rocks, classifying them based on observable properties. This lesson teaches students not only about rocks but also about how to take a closer look at objects and materials that they encounter every day. Students are encouraged to notice details that they may have previously overlooked. Students observe, test, and sort a collection of rocks using a variety of criteria including hardness, texture, luster, reaction to weak acid, magnetic attraction, and density. They then use Venn diagrams to group similar rocks.