Crystals are a special kind of solid material in which the molecules fit together in a repeating pattern. Crystals often form in nature when liquids cool and start to harden. We have found crystals in many of the rocks we have in the lab. The flat sides of crystals are called facets.
Third grade chemists made crystals using borax and boiling water. Click here to go to an About.com link that will explain how to make the crystals. There is also a video on the site.