This is a fun Easter Egg surprise.
You’ll need: an egg, a bowl or cup, water, and Borax
- Tap one end of the egg to break the shell and shake the egg shell so that the egg falls out. (Bake it in a strata if you’re so inclined!) 🙂
- Rinse the egg (inside and out) with water and prop it up in a bowl or cup.
- Heat water to just under boiling and remove from heat. Pour 1 cup of water into a heat safe measuring cup. Add 3 Tbs. Borax and stir to dissolve. Add more Borax, 1 tsp at a time, until you can’t dissolve anymore and you see a little bit start to settle at the bottom. (You might not need to add any extra after the 3 Tbs. per cup.
- Pour this solution into your empty egg shell
- Let the egg sit for a few days.
- Pour the liquid out and let dry overnight.
- Crack the egg shell for your big crystal reveal.
Here is what’s going on: This is a variation on our Crystal Hearts activity. In that experiment, we saw the sodium borate (Na2[B4O5(OH)4]·8H2O) from Borax crystallize onto a pipe cleaner to make a heart decoration. The same crystallization process is occurring here, but it is happening on the inside of the egg shell rather than on the pipe cleaner. We made a saturated solution (by adding Borax until no more dissolves) of the sodium borate in the water. As the water cools, some of the sodium borate comes out of solution (due to the solubility decreasing) and it starts to crystallize in this highly ordered structure. Molecules continue to deposit in this ordered structure as the water cools. Eventually the inside of the egg shell is covered and you have a fun surprise when you crack the egg.