Crystals Come In 4 Colors: Red, Green, Yellow And White. Let Your Child Feel Like A Real Chemist Mixing The Special Ingredients And Watching The Crystal Grow, A Beautiful Crystal In 7-10 Days With This Crystal Science Kit. Children Can Develop An Interest In Science Experiments By Growing Their Own Crystal Growing Kit.And When You'Re Done, Display It For All To Admire! Follow Along With The Beautifully Illustrated Booklet Describing How Crystals Are Formed. This Educational Stem Toys For Ages 8-12 Will Stimulate Children'S Thirst For Knowledge And Promote Children'S Spirit Of Exploring The World.