Four crystal trees, grown on your own windowsill Fill the test tubes with the crystal solution, place them in the four trees, and then leave them alone. You will see the first tiny crystals within about 30 minutes, and the trees grow fully overnight — no heating, no mixing, nothing to plug in. The science behind it Crystals form when a substance like alum dissolves in water to make a solution. As the water evaporates, the solution becomes supersaturated — holding more dissolved material than it can keep in suspension.

The particles come out of the liquid and arrange themselves into neat, repeating patterns. That pattern is a crystal, and it is the same process that formed the minerals in every rock collection. Why four trees matters Growing four at once means you can compare. Put one somewhere warm and one somewhere cool, or check them at different intervals, and you can see how conditions change the way crystals form. It turns a single result into an experiment worth talking about. What's in the box 4 x Crystal Trees · Crystal Solution · Trays · Full Instructions Ages 5 and up. For use under adult supervision. Not suitable for children under five years.