Crystals are beautiful structures--yet they occur naturally in dirty and remote places. In the inquiry-based activity described here, students will enjoy the process of creating their own crystals and using microscopes to examine them. It demonstrates the process of mineral concentration and deposition. Upon completing this activity, students often express amazement when they see the final product--beautiful, clean crystals that have grown from a "dirty" test tube. (Contains 5 figures and 3 online resources.)