My daughter received these Crayola Crystal Effects Window Markers™ for Easter. I’m not sure if they are discontinued because I couldn’t find them on crayola.com other than a reference in a craft project. You write on glass, and they form crystals over a period of a few minutes. I had my ProScope HR at home to take some microscopic views of salt and some other crystals that we are using for our Minerals unit. The 8+1 Science website got me thinking about the essence of minerals, which is the interesting arrangements that atoms make. Of course, I already knew this, but I think I may emphasize this point a little more. Anyway, back from this digression, I wanted to take a time-lapse video of the crystallization. It uses humidity from the air, so it might be some sort of deliquescent material, with the crystallization taking place after whatever volatile solvents evaporate? (Please correct me on this if I’m wrong.) On my time lapse, the crystallization happened so quickly that one couldn’t see it, so I went with a real-time video. You can see the part where the crystallization happens below. It’s still darn fast, but I don’t have the frame rate on this microscope to slow it down.
My next plan is to freeze some water on a glass slide and watch it melt but play it in reverse.