Borax is a soft crystal mineral that is soluble, meaning that it can be dissolved in liquid (especially water). With this experiment we dissolved as much borax as possible in the hot water, creating a “supersaturated solution”.
Cold water doesn’t hold as much borax as hot water. So as the supersaturated borax and water solution cools down, the borax separates from the water and forms crystals on whatever is placed in the solution.
We made borax crystals with pipe cleaners, water and borax.