GROW YOUR OWN CRYSTALS -pour white vinegar over the limestone specimen and crystals start to form when the vinegar evaporates. Add a penny or food coloring for exciting crystal colors! CRACK OPEN GEODES--who knew such regular looking rocks were hiding such beautiful crystals inside! Manufacturered by Dancing Bear. WATCH "TV" ON A ROCK--satin spar specimen demonstrates basic fiber optic science STEM concepts 100% SATISFACTION GUARANTEE--we will gladly refund your money if you are not completely happy with your purchase--no worries. FUN & EDUCATIONAL SCIENCE ACTIVITIES--Explore 5 Experiments that teach Earth Science STEM principles.