1 RANDOM COLOR - This crystal growing set is a fun way to explore science and geology at home. This crystal growing kit includes everything needed to grow your own crystals trees at home. The set includes a plastic base and a cardboard tree with grow crystals. Add the clear solution to the base and watch as the tree quickly absorbs the water and creates tiny soft crystals. These crystal sets come in 4 different colors and are an easy to do STEM experiment for kids. Trees are about 6" tall. FYI - The crystals on this tree are soft and delicate, not hard like the other crystal growing set. These grow quickly! You will see progress within a few minutes. Crystallization occurs naturally when the liquid cools and hardens causing atoms to bind together in different ways. This ensures a unique pattern every single time a crystal is made, the perfect example of this is the uniqueness of snowflakes.