We have been trying to make crystals. We have done two experiments and both have not been great. The first one we used charcoal. There were little crystals but not as big as we would have like.
The second experiment we tried making sugar crystals. It has been a little better. You can see some forming on the picture below. I think I am going to leave this jars out for a couple of months and see what happens. (We need to have some days without rain).
Anyway, we have one more experiment we are going to try out. If you have any recipes for growing crystals we would love to try them.