Geology has never been more fun! Our break your own geode kit for kids includes 2 natural geo rocks that will provide you with a hands-on science experiment in the comfort of your own home. As water flows through the geode, additional mineral layers are deposited in its hollow interior. Over thousands of years, these layers of minerals build crystals that eventually fill the cavity and create a beautiful surprise for you to crack open! Give the geodes kit as a science gift for teens who have an interest in geology, science teachers, or simply as fun activity for young children. Simply use a small hammer to reveal the vibrant pink and blue crystal surprise hidden inside the geo rocks Each geode weights approximately 2 pounds but will vary in length and size.