Earth Science – Minerals
Math - Geometry
This set of crystal models includes seven systems. These include the six basic (cubic (isometric), hexagonal, tetragonal, orthorhombic, monoclinic, and triclinic), and a seventh (trigonal, or rhombohedral), which is a subdivision of the hexagonal system. This is sometimes shown as its own group based on the differences in their appearance from the hexagonal crystals.
The activity includes a model of each crystal form, labels for each, and a math connection that involves finding the face types on each crystal, as well as the number of vertices, edges, and faces. These can be hung according to given directions, or built and used then sent home. I’ve also had students build them, then glue them to construction paper as a 3-D display. If each model is copied on colored paper, it presents a more vivid representation and students love using the colored paper.