The boys and I have been making crystals. I have always wondered how these were made! We used this tutorial.
They come out as hard as rock and so sparkly! The boys were really excited to check on the crystals to see how they had grown.
We also made some spiral pipe cleaner crystals using a similar method. They are really pretty and I'm sure we will make some variations. There are many borax crystal ornament tutorials online too.
There were quite a few lessons in this for both boys. Mainly about saturation point and making a saturated solution. It is a very hands-on, visual and tactile lesson!
We also tried to make crystals with Epsom salts (below). We made lots of crystals but they were very small. We used the tutorial here for Crystal Needles.
All of these methods require a lot of parent support due to using hot water. Last but not least, we have a sugar crystal growing. It's too small to photograph right now but I will keep you posted!