Crystals can form when a liquid that contains a dissolved mineral cools. The hot water caused the water molecules to move further away from each other so that more of the borax could dissolve into the solution. In this activity, a solution was made using hot water and borax a soft crystal. once the borax can not dissolve in the water any more. Crystals can form when a supersaturated liquid that contains a dissolved mineral cools. In this activity, a supersaturated solution was made using hot water and borax (a soft crystal). The hot water caused the water molecules to move further away from each other so that more of the borax could dissolve into the solution. Once the solution reaches a point where it cannot dissolve any more borax, it becomes supersaturated. As the solution cools, the water molecules come closer together again causing the forming borax crystals to cling to the pipe cleaner.